lib/moodlelib.php

   1 <?php // $Id$
   2
   3 ///////////////////////////////////////////////////////////////////////////
   4 //                                                                       //
   5 // NOTICE OF COPYRIGHT                                                   //
   6 //                                                                       //
   7 // Moodle - Modular Object-Oriented Dynamic Learning Environment         //
   8 //          http://moodle.org                                            //
   9 //                                                                       //
  10 // Copyright (C) 1999-2004  Martin Dougiamas  http://dougiamas.com       //
  11 //                                                                       //
  12 // This program is free software; you can redistribute it and/or modify  //
  13 // it under the terms of the GNU General Public License as published by  //
  14 // the Free Software Foundation; either version 2 of the License, or     //
  15 // (at your option) any later version.                                   //
  16 //                                                                       //
  17 // This program is distributed in the hope that it will be useful,       //
  18 // but WITHOUT ANY WARRANTY; without even the implied warranty of        //
  19 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         //
  20 // GNU General Public License for more details:                          //
  21 //                                                                       //
  22 //          http://www.gnu.org/copyleft/gpl.html                         //
  23 //                                                                       //
  24 ///////////////////////////////////////////////////////////////////////////
  25
  26 /**
  27  * moodlelib.php - Moodle main library
  28  *
  29  * Main library file of miscellaneous general-purpose Moodle functions.
  30  * Other main libraries:
  31  *  - weblib.php      - functions that produce web output
  32  *  - datalib.php     - functions that access the database
  33  * @author Martin Dougiamas
  34  * @version $Id$
  35  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  36  * @package moodlecore
  37  */
  38
  39 /// CONSTANTS (Encased in phpdoc proper comments)/////////////////////////
  40
  41 /**
  42  * Used by some scripts to check they are being called by Moodle
  43  */
  44 define('MOODLE_INTERNAL', true);
  45
  46 /// Date and time constants ///
  47 /**
  48  * Time constant - the number of seconds in a year
  49  */
  50
  51 define('YEARSECS', 31536000);
  52
  53 /**
  54  * Time constant - the number of seconds in a week
  55  */
  56 define('WEEKSECS', 604800);
  57
  58 /**
  59  * Time constant - the number of seconds in a day
  60  */
  61 define('DAYSECS', 86400);
  62
  63 /**
  64  * Time constant - the number of seconds in an hour
  65  */
  66 define('HOURSECS', 3600);
  67
  68 /**
  69  * Time constant - the number of seconds in a minute
  70  */
  71 define('MINSECS', 60);
  72
  73 /**
  74  * Time constant - the number of minutes in a day
  75  */
  76 define('DAYMINS', 1440);
  77
  78 /**
  79  * Time constant - the number of minutes in an hour
  80  */
  81 define('HOURMINS', 60);
  82
  83 /// Parameter constants - every call to optional_param(), required_param()  ///
  84 /// or clean_param() should have a specified type of parameter.  //////////////
  85
  86 /**
  87  * PARAM_RAW specifies a parameter that is not cleaned/processed in any way;
  88  * originally was 0, but changed because we need to detect unknown
  89  * parameter types and swiched order in clean_param().
  90  */
  91 define('PARAM_RAW', 666);
  92
  93 /**
  94  * PARAM_CLEAN - obsoleted, please try to use more specific type of parameter.
  95  * It was one of the first types, that is why it is abused so much ;-)
  96  */
  97 define('PARAM_CLEAN',    0x0001);
  98
  99 /**
 100  * PARAM_INT - integers only, use when expecting only numbers.
 101  */
 102 define('PARAM_INT',      0x0002);
 103
 104 /**
 105  * PARAM_INTEGER - an alias for PARAM_INT
 106  */
 107 define('PARAM_INTEGER',  0x0002);
 108
 109 /**
 110  * PARAM_NUMBER - a real/floating point number.
 111  */
 112 define('PARAM_NUMBER',  0x000a);
 113
 114 /**
 115  * PARAM_ALPHA - contains only english letters.
 116  */
 117 define('PARAM_ALPHA',    0x0004);
 118
 119 /**
 120  * PARAM_ACTION - an alias for PARAM_ALPHA, use for various actions in formas and urls
 121  * @TODO: should we alias it to PARAM_ALPHANUM ?
 122  */
 123 define('PARAM_ACTION',   0x0004);
 124
 125 /**
 126  * PARAM_FORMAT - an alias for PARAM_ALPHA, use for names of plugins, formats, etc.
 127  * @TODO: should we alias it to PARAM_ALPHANUM ?
 128  */
 129 define('PARAM_FORMAT',   0x0004);
 130
 131 /**
 132  * PARAM_NOTAGS - all html tags are stripped from the text. Do not abuse this type.
 133  */
 134 define('PARAM_NOTAGS',   0x0008);
 135
 136  /**
 137  * PARAM_MULTILANG - alias of PARAM_TEXT.
 138  */
 139 define('PARAM_MULTILANG',  0x0009);
 140
 141  /**
 142  * PARAM_TEXT - general plain text compatible with multilang filter, no other html tags.
 143  */
 144 define('PARAM_TEXT',  0x0009);
 145
 146 /**
 147  * PARAM_FILE - safe file name, all dangerous chars are stripped, protects against XSS, SQL injections and directory traversals
 148  */
 149 define('PARAM_FILE',     0x0010);
 150
 151 /**
 152  * PARAM_TAG - one tag (interests, blogs, etc.) - mostly international alphanumeric with spaces
 153  */
 154 define('PARAM_TAG',   0x0011);
 155
 156 /**
 157  * PARAM_TAGLIST - list of tags separated by commas (interests, blogs, etc.)
 158  */
 159 define('PARAM_TAGLIST',   0x0012);
 160
 161 /**
 162  * PARAM_PATH - safe relative path name, all dangerous chars are stripped, protects against XSS, SQL injections and directory traversals
 163  * note: the leading slash is not removed, window drive letter is not allowed
 164  */
 165 define('PARAM_PATH',     0x0020);
 166
 167 /**
 168  * PARAM_HOST - expected fully qualified domain name (FQDN) or an IPv4 dotted quad (IP address)
 169  */
 170 define('PARAM_HOST',     0x0040);
 171
 172 /**
 173  * PARAM_URL - expected properly formatted URL. Please note that domain part is required, http://localhost/ is not acceppted but http://localhost.localdomain/ is ok.
 174  */
 175 define('PARAM_URL',      0x0080);
 176
 177 /**
 178  * PARAM_LOCALURL - expected properly formatted URL as well as one that refers to the local server itself. (NOT orthogonal to the others! Implies PARAM_URL!)
 179  */
 180 define('PARAM_LOCALURL', 0x0180);
 181
 182 /**
 183  * PARAM_CLEANFILE - safe file name, all dangerous and regional chars are removed,
 184  * use when you want to store a new file submitted by students
 185  */
 186 define('PARAM_CLEANFILE',0x0200);
 187
 188 /**
 189  * PARAM_ALPHANUM - expected numbers and letters only.
 190  */
 191 define('PARAM_ALPHANUM', 0x0400);
 192
 193 /**
 194  * PARAM_BOOL - converts input into 0 or 1, use for switches in forms and urls.
 195  */
 196 define('PARAM_BOOL',     0x0800);
 197
 198 /**
 199  * PARAM_CLEANHTML - cleans submitted HTML code and removes slashes
 200  * note: do not forget to addslashes() before storing into database!
 201  */
 202 define('PARAM_CLEANHTML',0x1000);
 203
 204 /**
 205  * PARAM_ALPHAEXT the same contents as PARAM_ALPHA plus the chars in quotes: "/-_" allowed,
 206  * suitable for include() and require()
 207  * @TODO: should we rename this function to PARAM_SAFEDIRS??
 208  */
 209 define('PARAM_ALPHAEXT', 0x2000);
 210
 211 /**
 212  * PARAM_SAFEDIR - safe directory name, suitable for include() and require()
 213  */
 214 define('PARAM_SAFEDIR',  0x4000);
 215
 216 /**
 217  * PARAM_SEQUENCE - expects a sequence of numbers like 8 to 1,5,6,4,6,8,9.  Numbers and comma only.
 218  */
 219 define('PARAM_SEQUENCE',  0x8000);
 220
 221 /**
 222  * PARAM_PEM - Privacy Enhanced Mail format
 223  */
 224 define('PARAM_PEM',      0x10000);
 225
 226 /**
 227  * PARAM_BASE64 - Base 64 encoded format
 228  */
 229 define('PARAM_BASE64',   0x20000);
 230
 231
 232 /// Page types ///
 233 /**
 234  * PAGE_COURSE_VIEW is a definition of a page type. For more information on the page class see moodle/lib/pagelib.php.
 235  */
 236 define('PAGE_COURSE_VIEW', 'course-view');
 237
 238 /// Debug levels ///
 239 /** no warnings at all */
 240 define ('DEBUG_NONE', 0);
 241 /** E_ERROR | E_PARSE */
 242 define ('DEBUG_MINIMAL', 5);
 243 /** E_ERROR | E_PARSE | E_WARNING | E_NOTICE */
 244 define ('DEBUG_NORMAL', 15);
 245 /** E_ALL without E_STRICT and E_RECOVERABLE_ERROR for now */
 246 define ('DEBUG_ALL', 2047);
 247 /** DEBUG_ALL with extra Moodle debug messages - (DEBUG_ALL | 32768) */
 248 define ('DEBUG_DEVELOPER', 34815);
 249
 250 /**
 251  * Blog access level constant declaration
 252  */
 253 define ('BLOG_USER_LEVEL', 1);
 254 define ('BLOG_GROUP_LEVEL', 2);
 255 define ('BLOG_COURSE_LEVEL', 3);
 256 define ('BLOG_SITE_LEVEL', 4);
 257 define ('BLOG_GLOBAL_LEVEL', 5);
 258
 259 /**
 260  * Tag constanst
 261  */
 262 define('TAG_MAX_LENGTH', 50);
 263
 264
 265
 266 /// PARAMETER HANDLING ////////////////////////////////////////////////////
 267
 268 /**
 269  * Returns a particular value for the named variable, taken from
 270  * POST or GET.  If the parameter doesn't exist then an error is
 271  * thrown because we require this variable.
 272  *
 273  * This function should be used to initialise all required values
 274  * in a script that are based on parameters.  Usually it will be
 275  * used like this:
 276  *    $id = required_param('id');
 277  *
 278  * @param string $parname the name of the page parameter we want
 279  * @param int $type expected type of parameter
 280  * @return mixed
 281  */
 282 function required_param($parname, $type=PARAM_CLEAN) {
 283
 284     // detect_unchecked_vars addition
 285     global $CFG;
 286     if (!empty($CFG->detect_unchecked_vars)) {
 287         global $UNCHECKED_VARS;
 288         unset ($UNCHECKED_VARS->vars[$parname]);
 289     }
 290
 291     if (isset($_POST[$parname])) {       // POST has precedence
 292         $param = $_POST[$parname];
 293     } else if (isset($_GET[$parname])) {
 294         $param = $_GET[$parname];
 295     } else {
 296         error('A required parameter ('.$parname.') was missing');
 297     }
 298
 299     return clean_param($param, $type);
 300 }
 301
 302 /**
 303  * Returns a particular value for the named variable, taken from
 304  * POST or GET, otherwise returning a given default.
 305  *
 306  * This function should be used to initialise all optional values
 307  * in a script that are based on parameters.  Usually it will be
 308  * used like this:
 309  *    $name = optional_param('name', 'Fred');
 310  *
 311  * @param string $parname the name of the page parameter we want
 312  * @param mixed  $default the default value to return if nothing is found
 313  * @param int $type expected type of parameter
 314  * @return mixed
 315  */
 316 function optional_param($parname, $default=NULL, $type=PARAM_CLEAN) {
 317
 318     // detect_unchecked_vars addition
 319     global $CFG;
 320     if (!empty($CFG->detect_unchecked_vars)) {
 321         global $UNCHECKED_VARS;
 322         unset ($UNCHECKED_VARS->vars[$parname]);
 323     }
 324
 325     if (isset($_POST[$parname])) {       // POST has precedence
 326         $param = $_POST[$parname];
 327     } else if (isset($_GET[$parname])) {
 328         $param = $_GET[$parname];
 329     } else {
 330         return $default;
 331     }
 332
 333     return clean_param($param, $type);
 334 }
 335
 336 /**
 337  * Used by {@link optional_param()} and {@link required_param()} to
 338  * clean the variables and/or cast to specific types, based on
 339  * an options field.
 340  * <code>
 341  * $course->format = clean_param($course->format, PARAM_ALPHA);
 342  * $selectedgrade_item = clean_param($selectedgrade_item, PARAM_CLEAN);
 343  * </code>
 344  *
 345  * @uses $CFG
 346  * @uses PARAM_CLEAN
 347  * @uses PARAM_INT
 348  * @uses PARAM_INTEGER
 349  * @uses PARAM_ALPHA
 350  * @uses PARAM_ALPHANUM
 351  * @uses PARAM_NOTAGS
 352  * @uses PARAM_ALPHAEXT
 353  * @uses PARAM_BOOL
 354  * @uses PARAM_SAFEDIR
 355  * @uses PARAM_CLEANFILE
 356  * @uses PARAM_FILE
 357  * @uses PARAM_PATH
 358  * @uses PARAM_HOST
 359  * @uses PARAM_URL
 360  * @uses PARAM_LOCALURL
 361  * @uses PARAM_CLEANHTML
 362  * @uses PARAM_SEQUENCE
 363  * @param mixed $param the variable we are cleaning
 364  * @param int $type expected format of param after cleaning.
 365  * @return mixed
 366  */
 367 function clean_param($param, $type) {
 368
 369     global $CFG;
 370
 371     if (is_array($param)) {              // Let's loop
 372         $newparam = array();
 373         foreach ($param as $key => $value) {
 374             $newparam[$key] = clean_param($value, $type);
 375         }
 376         return $newparam;
 377     }
 378
 379     switch ($type) {
 380         case PARAM_RAW:          // no cleaning at all
 381             return $param;
 382
 383         case PARAM_CLEAN:        // General HTML cleaning, try to use more specific type if possible
 384             if (is_numeric($param)) {
 385                 return $param;
 386             }
 387             $param = stripslashes($param);   // Needed for kses to work fine
 388             $param = clean_text($param);     // Sweep for scripts, etc
 389             return addslashes($param);       // Restore original request parameter slashes
 390
 391         case PARAM_CLEANHTML:    // prepare html fragment for display, do not store it into db!!
 392             $param = stripslashes($param);   // Remove any slashes
 393             $param = clean_text($param);     // Sweep for scripts, etc
 394             return trim($param);
 395
 396         case PARAM_INT:
 397             return (int)$param;  // Convert to integer
 398
 399         case PARAM_NUMBER:
 400             return (float)$param;  // Convert to integer
 401
 402         case PARAM_ALPHA:        // Remove everything not a-z
 403             return eregi_replace('[^a-zA-Z]', '', $param);
 404
 405         case PARAM_ALPHANUM:     // Remove everything not a-zA-Z0-9
 406             return eregi_replace('[^A-Za-z0-9]', '', $param);
 407
 408         case PARAM_ALPHAEXT:     // Remove everything not a-zA-Z/_-
 409             return eregi_replace('[^a-zA-Z/_-]', '', $param);
 410
 411         case PARAM_SEQUENCE:     // Remove everything not 0-9,
 412             return eregi_replace('[^0-9,]', '', $param);
 413
 414         case PARAM_BOOL:         // Convert to 1 or 0
 415             $tempstr = strtolower($param);
 416             if ($tempstr == 'on' or $tempstr == 'yes' ) {
 417                 $param = 1;
 418             } else if ($tempstr == 'off' or $tempstr == 'no') {
 419                 $param = 0;
 420             } else {
 421                 $param = empty($param) ? 0 : 1;
 422             }
 423             return $param;
 424
 425         case PARAM_NOTAGS:       // Strip all tags
 426             return strip_tags($param);
 427
 428         case PARAM_TEXT:    // leave only tags needed for multilang
 429             return clean_param(strip_tags($param, '<lang><span>'), PARAM_CLEAN);
 430
 431         case PARAM_SAFEDIR:      // Remove everything not a-zA-Z0-9_-
 432             return eregi_replace('[^a-zA-Z0-9_-]', '', $param);
 433
 434         case PARAM_CLEANFILE:    // allow only safe characters
 435             return clean_filename($param);
 436
 437         case PARAM_FILE:         // Strip all suspicious characters from filename
 438             $param = ereg_replace('[[:cntrl:]]|[<>"`\|\':\\/]', '', $param);
 439             $param = ereg_replace('\.\.+', '', $param);
 440             if($param == '.') {
 441                 $param = '';
 442             }
 443             return $param;
 444
 445         case PARAM_PATH:         // Strip all suspicious characters from file path
 446             $param = str_replace('\\\'', '\'', $param);
 447             $param = str_replace('\\"', '"', $param);
 448             $param = str_replace('\\', '/', $param);
 449             $param = ereg_replace('[[:cntrl:]]|[<>"`\|\':]', '', $param);
 450             $param = ereg_replace('\.\.+', '', $param);
 451             $param = ereg_replace('//+', '/', $param);
 452             return ereg_replace('/(\./)+', '/', $param);
 453
 454         case PARAM_HOST:         // allow FQDN or IPv4 dotted quad
 455             preg_replace('/[^\.\d\w-]/','', $param ); // only allowed chars
 456             // match ipv4 dotted quad
 457             if (preg_match('/(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/',$param, $match)){
 458                 // confirm values are ok
 459                 if ( $match[0] > 255
 460                      || $match[1] > 255
 461                      || $match[3] > 255
 462                      || $match[4] > 255 ) {
 463                     // hmmm, what kind of dotted quad is this?
 464                     $param = '';
 465                 }
 466             } elseif ( preg_match('/^[\w\d\.-]+$/', $param) // dots, hyphens, numbers
 467                        && !preg_match('/^[\.-]/',  $param) // no leading dots/hyphens
 468                        && !preg_match('/[\.-]$/',  $param) // no trailing dots/hyphens
 469                        ) {
 470                 // all is ok - $param is respected
 471             } else {
 472                 // all is not ok...
 473                 $param='';
 474             }
 475             return $param;
 476
 477         case PARAM_URL:          // allow safe ftp, http, mailto urls
 478             include_once($CFG->dirroot . '/lib/validateurlsyntax.php');
 479             if (!empty($param) && validateUrlSyntax($param, 's?H?S?F?E?u-P-a?I?p?f?q?r?')) {
 480                 // all is ok, param is respected
 481             } else {
 482                 $param =''; // not really ok
 483             }
 484             return $param;
 485
 486         case PARAM_LOCALURL:     // allow http absolute, root relative and relative URLs within wwwroot
 487             $param = clean_param($param, PARAM_URL);
 488             if (!empty($param)) {
 489                 if (preg_match(':^/:', $param)) {
 490                     // root-relative, ok!
 491                 } elseif (preg_match('/^'.preg_quote($CFG->wwwroot, '/').'/i',$param)) {
 492                     // absolute, and matches our wwwroot
 493                 } else {
 494                     // relative - let's make sure there are no tricks
 495                     if (validateUrlSyntax($param, 's-u-P-a-p-f+q?r?')) {
 496                         // looks ok.
 497                     } else {
 498                         $param = '';
 499                     }
 500                 }
 501             }
 502             return $param;
 503
 504         case PARAM_PEM:
 505             $param = trim($param);
 506             // PEM formatted strings may contain letters/numbers and the symbols
 507             // forward slash: /
 508             // plus sign:     +
 509             // equal sign:    =
 510             // , surrounded by BEGIN and END CERTIFICATE prefix and suffixes
 511             if (preg_match('/^-----BEGIN CERTIFICATE-----([\s\w\/\+=]+)-----END CERTIFICATE-----$/', trim($param), $matches)) {
 512                 list($wholething, $body) = $matches;
 513                 unset($wholething, $matches);
 514                 $b64 = clean_param($body, PARAM_BASE64);
 515                 if (!empty($b64)) {
 516                     return "-----BEGIN CERTIFICATE-----\n$b64\n-----END CERTIFICATE-----\n";
 517                 } else {
 518                     return '';
 519                 }
 520             }
 521             return '';
 522
 523         case PARAM_BASE64:
 524             if (!empty($param)) {
 525                 // PEM formatted strings may contain letters/numbers and the symbols
 526                 // forward slash: /
 527                 // plus sign:     +
 528                 // equal sign:    =
 529                 if (0 >= preg_match('/^([\s\w\/\+=]+)$/', trim($param))) {
 530                     return '';
 531                 }
 532                 $lines = preg_split('/[\s]+/', $param, -1, PREG_SPLIT_NO_EMPTY);
 533                 // Each line of base64 encoded data must be 64 characters in
 534                 // length, except for the last line which may be less than (or
 535                 // equal to) 64 characters long.
 536                 for ($i=0, $j=count($lines); $i < $j; $i++) {
 537                     if ($i + 1 == $j) {
 538                         if (64 < strlen($lines[$i])) {
 539                             return '';
 540                         }
 541                         continue;
 542                     }
 543
 544                     if (64 != strlen($lines[$i])) {
 545                         return '';
 546                     }
 547                 }
 548                 return implode("\n",$lines);
 549             } else {
 550                 return '';
 551             }
 552
 553         case PARAM_TAG:
 554             //first fix whitespace
 555             $param = preg_replace('/\s+/', ' ', $param);
 556             //remove blacklisted ASCII ranges of chars - security FIRST - keep only ascii letters, numnbers and spaces
 557             //the result should be safe to be used directly in html and SQL
 558             $param = preg_replace("/[\\000-\\x1f\\x21-\\x2f\\x3a-\\x40\\x5b-\\x60\\x7b-\\x7f]/", '', $param);
 559             //now remove some unicode ranges we do not want
 560             $param = preg_replace("/[\\x{80}-\\x{bf}\\x{d7}\\x{f7}]/u", '', $param);
 561             //cleanup the spaces
 562             $param = preg_replace('/ +/', ' ', $param);
 563             $param = trim($param);
 564             $textlib = textlib_get_instance();
 565             $param = $textlib->substr($param, 0, TAG_MAX_LENGTH);
 566             //numeric tags not allowed
 567             return is_numeric($param) ? '' : $param;
 568
 569         case PARAM_TAGLIST:
 570             $tags = explode(',', $param);
 571             $result = array();
 572             foreach ($tags as $tag) {
 573                 $res = clean_param($tag, PARAM_TAG);
 574                 if ($res != '') {
 575                     $result[] = $res;
 576                 }
 577             }
 578             if ($result) {
 579                 return implode(',', $result);
 580             } else {
 581                 return '';
 582             }
 583
 584         default:                 // throw error, switched parameters in optional_param or another serious problem
 585             error("Unknown parameter type: $type");
 586     }
 587 }
 588
 589
 590
 591 /**
 592  * Set a key in global configuration
 593  *
 594  * Set a key/value pair in both this session's {@link $CFG} global variable
 595  * and in the 'config' database table for future sessions.
 596  *
 597  * Can also be used to update keys for plugin-scoped configs in config_plugin table.
 598  * In that case it doesn't affect $CFG.
 599  *
 600  * @param string $name the key to set
 601  * @param string $value the value to set (without magic quotes)
 602  * @param string $plugin (optional) the plugin scope
 603  * @uses $CFG
 604  * @return bool
 605  */
 606 function set_config($name, $value, $plugin=NULL) {
 607 /// No need for get_config because they are usually always available in $CFG
 608
 609     global $CFG;
 610
 611     if (empty($plugin)) {
 612         $CFG->$name = $value;  // So it's defined for this invocation at least
 613
 614         if (get_field('config', 'name', 'name', $name)) {
 615             return set_field('config', 'value', addslashes($value), 'name', $name);
 616         } else {
 617             $config = new object();
 618             $config->name = $name;
 619             $config->value = addslashes($value);
 620             return insert_record('config', $config);
 621         }
 622     } else { // plugin scope
 623         if ($id = get_field('config_plugins', 'id', 'name', $name, 'plugin', $plugin)) {
 624             return set_field('config_plugins', 'value', addslashes($value), 'id', $id);
 625         } else {
 626             $config = new object();
 627             $config->plugin = addslashes($plugin);
 628             $config->name   = $name;
 629             $config->value  = addslashes($value);
 630             return insert_record('config_plugins', $config);
 631         }
 632     }
 633 }
 634
 635 /**
 636  * Get configuration values from the global config table
 637  * or the config_plugins table.
 638  *
 639  * If called with no parameters it will do the right thing
 640  * generating $CFG safely from the database without overwriting
 641  * existing values.
 642  *
 643  * If called with 2 parameters it will return a $string single
 644  * value or false of the value is not found.
 645  *
 646  * @param string $plugin
 647  * @param string $name
 648  * @uses $CFG
 649  * @return hash-like object or single value
 650  *
 651  */
 652 function get_config($plugin=NULL, $name=NULL) {
 653
 654     global $CFG;
 655
 656     if (!empty($name)) { // the user is asking for a specific value
 657         if (!empty($plugin)) {
 658             return get_field('config_plugins', 'value', 'plugin' , $plugin, 'name', $name);
 659         } else {
 660             return get_field('config', 'value', 'name', $name);
 661         }
 662     }
 663
 664     // the user is after a recordset
 665     if (!empty($plugin)) {
 666         if ($configs=get_records('config_plugins', 'plugin', $plugin, '', 'name,value')) {
 667             $configs = (array)$configs;
 668             $localcfg = array();
 669             foreach ($configs as $config) {
 670                 $localcfg[$config->name] = $config->value;
 671             }
 672             return (object)$localcfg;
 673         } else {
 674             return false;
 675         }
 676     } else {
 677         // this was originally in setup.php
 678         if ($configs = get_records('config')) {
 679             $localcfg = (array)$CFG;
 680             foreach ($configs as $config) {
 681                 if (!isset($localcfg[$config->name])) {
 682                     $localcfg[$config->name] = $config->value;
 683                 } else {
 684                     if ($localcfg[$config->name] != $config->value ) {
 685                         // complain if the DB has a different
 686                         // value than config.php does
 687                         error_log("\$CFG->{$config->name} in config.php ({$localcfg[$config->name]}) overrides database setting ({$config->value})");
 688                     }
 689                 }
 690             }
 691
 692             $localcfg = (object)$localcfg;
 693             return $localcfg;
 694         } else {
 695             // preserve $CFG if DB returns nothing or error
 696             return $CFG;
 697         }
 698
 699     }
 700 }
 701
 702 /**
 703  * Removes a key from global configuration
 704  *
 705  * @param string $name the key to set
 706  * @param string $plugin (optional) the plugin scope
 707  * @uses $CFG
 708  * @return bool
 709  */
 710 function unset_config($name, $plugin=NULL) {
 711
 712     global $CFG;
 713
 714     unset($CFG->$name);
 715
 716     if (empty($plugin)) {
 717         return delete_records('config', 'name', $name);
 718     } else {
 719         return delete_records('config_plugins', 'name', $name, 'plugin', $plugin);
 720     }
 721 }
 722
 723
 724 /**
 725  * Refresh current $USER session global variable with all their current preferences.
 726  * @uses $USER
 727  */
 728 function reload_user_preferences() {
 729
 730     global $USER;
 731
 732     //reset preference
 733     $USER->preference = array();
 734
 735     if (!isloggedin() or isguestuser()) {
 736         // no pernament storage for not-logged-in user and guest
 737
 738     } else if ($preferences = get_records('user_preferences', 'userid', $USER->id)) {
 739         foreach ($preferences as $preference) {
 740             $USER->preference[$preference->name] = $preference->value;
 741         }
 742     }
 743
 744     return true;
 745 }
 746
 747 /**
 748  * Sets a preference for the current user
 749  * Optionally, can set a preference for a different user object
 750  * @uses $USER
 751  * @todo Add a better description and include usage examples. Add inline links to $USER and user functions in above line.
 752
 753  * @param string $name The key to set as preference for the specified user
 754  * @param string $value The value to set forthe $name key in the specified user's record
 755  * @param int $otheruserid A moodle user ID
 756  * @return bool
 757  */
 758 function set_user_preference($name, $value, $otheruserid=NULL) {
 759
 760     global $USER;
 761
 762     if (!isset($USER->preference)) {
 763         reload_user_preferences();
 764     }
 765
 766     if (empty($name)) {
 767         return false;
 768     }
 769
 770     $nostore = false;
 771
 772     if (empty($otheruserid)){
 773         if (!isloggedin() or isguestuser()) {
 774             $nostore = true;
 775         }
 776         $userid = $USER->id;
 777     } else {
 778         if (isguestuser($otheruserid)) {
 779             $nostore = true;
 780         }
 781         $userid = $otheruserid;
 782     }
 783
 784     $return = true;
 785     if ($nostore) {
 786         // no pernament storage for not-logged-in user and guest
 787
 788     } else if ($preference = get_record('user_preferences', 'userid', $userid, 'name', addslashes($name))) {
 789         if ($preference->value === $value) {
 790             return true;
 791         }
 792         if (!set_field('user_preferences', 'value', addslashes((string)$value), 'id', $preference->id)) {
 793             $return = false;
 794         }
 795
 796     } else {
 797         $preference = new object();
 798         $preference->userid = $userid;
 799         $preference->name   = addslashes($name);
 800         $preference->value  = addslashes((string)$value);
 801         if (!insert_record('user_preferences', $preference)) {
 802             $return = false;
 803         }
 804     }
 805
 806     // update value in USER session if needed
 807     if ($userid == $USER->id) {
 808         $USER->preference[$name] = (string)$value;
 809     }
 810
 811     return $return;
 812 }
 813
 814 /**
 815  * Unsets a preference completely by deleting it from the database
 816  * Optionally, can set a preference for a different user id
 817  * @uses $USER
 818  * @param string  $name The key to unset as preference for the specified user
 819  * @param int $otheruserid A moodle user ID
 820  */
 821 function unset_user_preference($name, $otheruserid=NULL) {
 822
 823     global $USER;
 824
 825     if (!isset($USER->preference)) {
 826         reload_user_preferences();
 827     }
 828
 829     if (empty($otheruserid)){
 830         $userid = $USER->id;
 831     } else {
 832         $userid = $otheruserid;
 833     }
 834
 835     //Delete the preference from $USER if needed
 836     if ($userid == $USER->id) {
 837         unset($USER->preference[$name]);
 838     }
 839
 840     //Then from DB
 841     return delete_records('user_preferences', 'userid', $userid, 'name', addslashes($name));
 842 }
 843
 844
 845 /**
 846  * Sets a whole array of preferences for the current user
 847  * @param array $prefarray An array of key/value pairs to be set
 848  * @param int $otheruserid A moodle user ID
 849  * @return bool
 850  */
 851 function set_user_preferences($prefarray, $otheruserid=NULL) {
 852
 853     if (!is_array($prefarray) or empty($prefarray)) {
 854         return false;
 855     }
 856
 857     $return = true;
 858     foreach ($prefarray as $name => $value) {
 859         // The order is important; test for return is done first
 860         $return = (set_user_preference($name, $value, $otheruserid) && $return);
 861     }
 862     return $return;
 863 }
 864
 865 /**
 866  * If no arguments are supplied this function will return
 867  * all of the current user preferences as an array.
 868  * If a name is specified then this function
 869  * attempts to return that particular preference value.  If
 870  * none is found, then the optional value $default is returned,
 871  * otherwise NULL.
 872  * @param string $name Name of the key to use in finding a preference value
 873  * @param string $default Value to be returned if the $name key is not set in the user preferences
 874  * @param int $otheruserid A moodle user ID
 875  * @uses $USER
 876  * @return string
 877  */
 878 function get_user_preferences($name=NULL, $default=NULL, $otheruserid=NULL) {
 879     global $USER;
 880
 881     if (!isset($USER->preference)) {
 882         reload_user_preferences();
 883     }
 884
 885     if (empty($otheruserid)){
 886         $userid = $USER->id;
 887     } else {
 888         $userid = $otheruserid;
 889     }
 890
 891     if ($userid == $USER->id) {
 892         $preference = $USER->preference;
 893
 894     } else {
 895         $preference = array();
 896         if ($prefdata = get_records('user_preferences', 'userid', $userid)) {
 897             foreach ($prefdata as $pref) {
 898                 $preference[$pref->name] = $pref->value;
 899             }
 900         }
 901     }
 902
 903     if (empty($name)) {
 904         return $preference;            // All values
 905
 906     } else if (array_key_exists($name, $preference)) {
 907         return $preference[$name];    // The single value
 908
 909     } else {
 910         return $default;              // Default value (or NULL)
 911     }
 912 }
 913
 914
 915 /// FUNCTIONS FOR HANDLING TIME ////////////////////////////////////////////
 916
 917 /**
 918  * Given date parts in user time produce a GMT timestamp.
 919  *
 920  * @param int $year The year part to create timestamp of
 921  * @param int $month The month part to create timestamp of
 922  * @param int $day The day part to create timestamp of
 923  * @param int $hour The hour part to create timestamp of
 924  * @param int $minute The minute part to create timestamp of
 925  * @param int $second The second part to create timestamp of
 926  * @param float $timezone ?
 927  * @param bool $applydst ?
 928  * @return int timestamp
 929  * @todo Finish documenting this function
 930  */
 931 function make_timestamp($year, $month=1, $day=1, $hour=0, $minute=0, $second=0, $timezone=99, $applydst=true) {
 932
 933     $timezone = get_user_timezone_offset($timezone);
 934
 935     if (abs($timezone) > 13) {
 936         $time = mktime((int)$hour, (int)$minute, (int)$second, (int)$month, (int)$day, (int)$year);
 937     } else {
 938         $time = gmmktime((int)$hour, (int)$minute, (int)$second, (int)$month, (int)$day, (int)$year);
 939         $time = usertime($time, $timezone);
 940         if($applydst) {
 941             $time -= dst_offset_on($time);
 942         }
 943     }
 944
 945     return $time;
 946
 947 }
 948
 949 /**
 950  * Given an amount of time in seconds, returns string
 951  * formatted nicely as weeks, days, hours etc as needed
 952  *
 953  * @uses MINSECS
 954  * @uses HOURSECS
 955  * @uses DAYSECS
 956  * @uses YEARSECS
 957  * @param int $totalsecs ?
 958  * @param array $str ?
 959  * @return string
 960  */
 961  function format_time($totalsecs, $str=NULL) {
 962
 963     $totalsecs = abs($totalsecs);
 964
 965     if (!$str) {  // Create the str structure the slow way
 966         $str->day   = get_string('day');
 967         $str->days  = get_string('days');
 968         $str->hour  = get_string('hour');
 969         $str->hours = get_string('hours');
 970         $str->min   = get_string('min');
 971         $str->mins  = get_string('mins');
 972         $str->sec   = get_string('sec');
 973         $str->secs  = get_string('secs');
 974         $str->year  = get_string('year');
 975         $str->years = get_string('years');
 976     }
 977
 978
 979     $years     = floor($totalsecs/YEARSECS);
 980     $remainder = $totalsecs - ($years*YEARSECS);
 981     $days      = floor($remainder/DAYSECS);
 982     $remainder = $totalsecs - ($days*DAYSECS);
 983     $hours     = floor($remainder/HOURSECS);
 984     $remainder = $remainder - ($hours*HOURSECS);
 985     $mins      = floor($remainder/MINSECS);
 986     $secs      = $remainder - ($mins*MINSECS);
 987
 988     $ss = ($secs == 1)  ? $str->sec  : $str->secs;
 989     $sm = ($mins == 1)  ? $str->min  : $str->mins;
 990     $sh = ($hours == 1) ? $str->hour : $str->hours;
 991     $sd = ($days == 1)  ? $str->day  : $str->days;
 992     $sy = ($years == 1)  ? $str->year  : $str->years;
 993
 994     $oyears = '';
 995     $odays = '';
 996     $ohours = '';
 997     $omins = '';
 998     $osecs = '';
 999
1000     if ($years)  $oyears  = $years .' '. $sy;
1001     if ($days)  $odays  = $days .' '. $sd;
1002     if ($hours) $ohours = $hours .' '. $sh;
1003     if ($mins)  $omins  = $mins .' '. $sm;
1004     if ($secs)  $osecs  = $secs .' '. $ss;
1005
1006     if ($years) return trim($oyears .' '. $odays);
1007     if ($days)  return trim($odays .' '. $ohours);
1008     if ($hours) return trim($ohours .' '. $omins);
1009     if ($mins)  return trim($omins .' '. $osecs);
1010     if ($secs)  return $osecs;
1011     return get_string('now');
1012 }
1013
1014 /**
1015  * Returns a formatted string that represents a date in user time
1016  * <b>WARNING: note that the format is for strftime(), not date().</b>
1017  * Because of a bug in most Windows time libraries, we can't use
1018  * the nicer %e, so we have to use %d which has leading zeroes.
1019  * A lot of the fuss in the function is just getting rid of these leading
1020  * zeroes as efficiently as possible.
1021  *
1022  * If parameter fixday = true (default), then take off leading
1023  * zero from %d, else mantain it.
1024  *
1025  * @uses HOURSECS
1026  * @param  int $date timestamp in GMT
1027  * @param string $format strftime format
1028  * @param float $timezone
1029  * @param bool $fixday If true (default) then the leading
1030  * zero from %d is removed. If false then the leading zero is mantained.
1031  * @return string
1032  */
1033 function userdate($date, $format='', $timezone=99, $fixday = true) {
1034
1035     global $CFG;
1036
1037     if (empty($format)) {
1038         $format = get_string('strftimedaydatetime');
1039     }
1040
1041     if (!empty($CFG->nofixday)) {  // Config.php can force %d not to be fixed.
1042         $fixday = false;
1043     } else if ($fixday) {
1044         $formatnoday = str_replace('%d', 'DD', $format);
1045         $fixday = ($formatnoday != $format);
1046     }
1047
1048     $date += dst_offset_on($date);
1049
1050     $timezone = get_user_timezone_offset($timezone);
1051
1052     if (abs($timezone) > 13) {   /// Server time
1053         if ($fixday) {
1054             $datestring = strftime($formatnoday, $date);
1055             $daystring  = str_replace(' 0', '', strftime(' %d', $date));
1056             $datestring = str_replace('DD', $daystring, $datestring);
1057         } else {
1058             $datestring = strftime($format, $date);
1059         }
1060     } else {
1061         $date += (int)($timezone * 3600);
1062         if ($fixday) {
1063             $datestring = gmstrftime($formatnoday, $date);
1064             $daystring  = str_replace(' 0', '', gmstrftime(' %d', $date));
1065             $datestring = str_replace('DD', $daystring, $datestring);
1066         } else {
1067             $datestring = gmstrftime($format, $date);
1068         }
1069     }
1070
1071 /// If we are running under Windows convert from windows encoding to UTF-8
1072 /// (because it's impossible to specify UTF-8 to fetch locale info in Win32)
1073
1074    if ($CFG->ostype == 'WINDOWS') {
1075        if ($localewincharset = get_string('localewincharset')) {
1076            $textlib = textlib_get_instance();
1077            $datestring = $textlib->convert($datestring, $localewincharset, 'utf-8');
1078        }
1079    }
1080
1081     return $datestring;
1082 }
1083
1084 /**
1085  * Given a $time timestamp in GMT (seconds since epoch),
1086  * returns an array that represents the date in user time
1087  *
1088  * @uses HOURSECS
1089  * @param int $time Timestamp in GMT
1090  * @param float $timezone ?
1091  * @return array An array that represents the date in user time
1092  * @todo Finish documenting this function
1093  */
1094 function usergetdate($time, $timezone=99) {
1095
1096     $timezone = get_user_timezone_offset($timezone);
1097
1098     if (abs($timezone) > 13) {    // Server time
1099         return getdate($time);
1100     }
1101
1102     // There is no gmgetdate so we use gmdate instead
1103     $time += dst_offset_on($time);
1104     $time += intval((float)$timezone * HOURSECS);
1105
1106     $datestring = gmstrftime('%S_%M_%H_%d_%m_%Y_%w_%j_%A_%B', $time);
1107
1108     list(
1109         $getdate['seconds'],
1110         $getdate['minutes'],
1111         $getdate['hours'],
1112         $getdate['mday'],
1113         $getdate['mon'],
1114         $getdate['year'],
1115         $getdate['wday'],
1116         $getdate['yday'],
1117         $getdate['weekday'],
1118         $getdate['month']
1119     ) = explode('_', $datestring);
1120
1121     return $getdate;
1122 }
1123
1124 /**
1125  * Given a GMT timestamp (seconds since epoch), offsets it by
1126  * the timezone.  eg 3pm in India is 3pm GMT - 7 * 3600 seconds
1127  *
1128  * @uses HOURSECS
1129  * @param  int $date Timestamp in GMT
1130  * @param float $timezone
1131  * @return int
1132  */
1133 function usertime($date, $timezone=99) {
1134
1135     $timezone = get_user_timezone_offset($timezone);
1136
1137     if (abs($timezone) > 13) {
1138         return $date;
1139     }
1140     return $date - (int)($timezone * HOURSECS);
1141 }
1142
1143 /**
1144  * Given a time, return the GMT timestamp of the most recent midnight
1145  * for the current user.
1146  *
1147  * @param int $date Timestamp in GMT
1148  * @param float $timezone ?
1149  * @return ?
1150  */
1151 function usergetmidnight($date, $timezone=99) {
1152
1153     $timezone = get_user_timezone_offset($timezone);
1154     $userdate = usergetdate($date, $timezone);
1155
1156     // Time of midnight of this user's day, in GMT
1157     return make_timestamp($userdate['year'], $userdate['mon'], $userdate['mday'], 0, 0, 0, $timezone);
1158
1159 }
1160
1161 /**
1162  * Returns a string that prints the user's timezone
1163  *
1164  * @param float $timezone The user's timezone
1165  * @return string
1166  */
1167 function usertimezone($timezone=99) {
1168
1169     $tz = get_user_timezone($timezone);
1170
1171     if (!is_float($tz)) {
1172         return $tz;
1173     }
1174
1175     if(abs($tz) > 13) { // Server time
1176         return get_string('serverlocaltime');
1177     }
1178
1179     if($tz == intval($tz)) {
1180         // Don't show .0 for whole hours
1181         $tz = intval($tz);
1182     }
1183
1184     if($tz == 0) {
1185         return 'GMT';
1186     }
1187     else if($tz > 0) {
1188         return 'GMT+'.$tz;
1189     }
1190     else {
1191         return 'GMT'.$tz;
1192     }
1193
1194 }
1195
1196 /**
1197  * Returns a float which represents the user's timezone difference from GMT in hours
1198  * Checks various settings and picks the most dominant of those which have a value
1199  *
1200  * @uses $CFG
1201  * @uses $USER
1202  * @param float $tz If this value is provided and not equal to 99, it will be returned as is and no other settings will be checked
1203  * @return int
1204  */
1205 function get_user_timezone_offset($tz = 99) {
1206
1207     global $USER, $CFG;
1208
1209     $tz = get_user_timezone($tz);
1210
1211     if (is_float($tz)) {
1212         return $tz;
1213     } else {
1214         $tzrecord = get_timezone_record($tz);
1215         if (empty($tzrecord)) {
1216             return 99.0;
1217         }
1218         return (float)$tzrecord->gmtoff / HOURMINS;
1219     }
1220 }
1221
1222 /**
1223  * Returns a float or a string which denotes the user's timezone
1224  * A float value means that a simple offset from GMT is used, while a string (it will be the name of a timezone in the database)
1225  * means that for this timezone there are also DST rules to be taken into account
1226  * Checks various settings and picks the most dominant of those which have a value
1227  *
1228  * @uses $USER
1229  * @uses $CFG
1230  * @param float $tz If this value is provided and not equal to 99, it will be returned as is and no other settings will be checked
1231  * @return mixed
1232  */
1233 function get_user_timezone($tz = 99) {
1234     global $USER, $CFG;
1235
1236     $timezones = array(
1237         $tz,
1238         isset($CFG->forcetimezone) ? $CFG->forcetimezone : 99,
1239         isset($USER->timezone) ? $USER->timezone : 99,
1240         isset($CFG->timezone) ? $CFG->timezone : 99,
1241         );
1242
1243     $tz = 99;
1244
1245     while(($tz == '' || $tz == 99) && $next = each($timezones)) {
1246         $tz = $next['value'];
1247     }
1248
1249     return is_numeric($tz) ? (float) $tz : $tz;
1250 }
1251
1252 /**
1253  * ?
1254  *
1255  * @uses $CFG
1256  * @uses $db
1257  * @param string $timezonename ?
1258  * @return object
1259  */
1260 function get_timezone_record($timezonename) {
1261     global $CFG, $db;
1262     static $cache = NULL;
1263
1264     if ($cache === NULL) {
1265         $cache = array();
1266     }
1267
1268     if (isset($cache[$timezonename])) {
1269         return $cache[$timezonename];
1270     }
1271
1272     return $cache[$timezonename] = get_record_sql('SELECT * FROM '.$CFG->prefix.'timezone
1273                                       WHERE name = '.$db->qstr($timezonename).' ORDER BY year DESC', true);
1274 }
1275
1276 /**
1277  * ?
1278  *
1279  * @uses $CFG
1280  * @uses $USER
1281  * @param ? $fromyear ?
1282  * @param ? $to_year ?
1283  * @return bool
1284  */
1285 function calculate_user_dst_table($from_year = NULL, $to_year = NULL) {
1286     global $CFG, $SESSION;
1287
1288     $usertz = get_user_timezone();
1289
1290     if (is_float($usertz)) {
1291         // Trivial timezone, no DST
1292         return false;
1293     }
1294
1295     if (!empty($SESSION->dst_offsettz) && $SESSION->dst_offsettz != $usertz) {
1296         // We have precalculated values, but the user's effective TZ has changed in the meantime, so reset
1297         unset($SESSION->dst_offsets);
1298         unset($SESSION->dst_range);
1299     }
1300
1301     if (!empty($SESSION->dst_offsets) && empty($from_year) && empty($to_year)) {
1302         // Repeat calls which do not request specific year ranges stop here, we have already calculated the table
1303         // This will be the return path most of the time, pretty light computationally
1304         return true;
1305     }
1306
1307     // Reaching here means we either need to extend our table or create it from scratch
1308
1309     // Remember which TZ we calculated these changes for
1310     $SESSION->dst_offsettz = $usertz;
1311
1312     if(empty($SESSION->dst_offsets)) {
1313         // If we 're creating from scratch, put the two guard elements in there
1314         $SESSION->dst_offsets = array(1 => NULL, 0 => NULL);
1315     }
1316     if(empty($SESSION->dst_range)) {
1317         // If creating from scratch
1318         $from = max((empty($from_year) ? intval(date('Y')) - 3 : $from_year), 1971);
1319         $to   = min((empty($to_year)   ? intval(date('Y')) + 3 : $to_year),   2035);
1320
1321         // Fill in the array with the extra years we need to process
1322         $yearstoprocess = array();
1323         for($i = $from; $i <= $to; ++$i) {
1324             $yearstoprocess[] = $i;
1325         }
1326
1327         // Take note of which years we have processed for future calls
1328         $SESSION->dst_range = array($from, $to);
1329     }
1330     else {
1331         // If needing to extend the table, do the same
1332         $yearstoprocess = array();
1333
1334         $from = max((empty($from_year) ? $SESSION->dst_range[0] : $from_year), 1971);
1335         $to   = min((empty($to_year)   ? $SESSION->dst_range[1] : $to_year),   2035);
1336
1337         if($from < $SESSION->dst_range[0]) {
1338             // Take note of which years we need to process and then note that we have processed them for future calls
1339             for($i = $from; $i < $SESSION->dst_range[0]; ++$i) {
1340                 $yearstoprocess[] = $i;
1341             }
1342             $SESSION->dst_range[0] = $from;
1343         }
1344         if($to > $SESSION->dst_range[1]) {
1345             // Take note of which years we need to process and then note that we have processed them for future calls
1346             for($i = $SESSION->dst_range[1] + 1; $i <= $to; ++$i) {
1347                 $yearstoprocess[] = $i;
1348             }
1349             $SESSION->dst_range[1] = $to;
1350         }
1351     }
1352
1353     if(empty($yearstoprocess)) {
1354         // This means that there was a call requesting a SMALLER range than we have already calculated
1355         return true;
1356     }
1357
1358     // From now on, we know that the array has at least the two guard elements, and $yearstoprocess has the years we need
1359     // Also, the array is sorted in descending timestamp order!
1360
1361     // Get DB data
1362     $presetrecords = get_records('timezone', 'name', $usertz, 'year DESC', 'year, gmtoff, dstoff, dst_month, dst_startday, dst_weekday, dst_skipweeks, dst_time, std_month, std_startday, std_weekday, std_skipweeks, std_time');
1363     if(empty($presetrecords)) {
1364         return false;
1365     }
1366
1367     // Remove ending guard (first element of the array)
1368     reset($SESSION->dst_offsets);
1369     unset($SESSION->dst_offsets[key($SESSION->dst_offsets)]);
1370
1371     // Add all required change timestamps
1372     foreach($yearstoprocess as $y) {
1373         // Find the record which is in effect for the year $y
1374         foreach($presetrecords as $year => $preset) {
1375             if($year <= $y) {
1376                 break;
1377             }
1378         }
1379
1380         $changes = dst_changes_for_year($y, $preset);
1381
1382         if($changes === NULL) {
1383             continue;
1384         }
1385         if($changes['dst'] != 0) {
1386             $SESSION->dst_offsets[$changes['dst']] = $preset->dstoff * MINSECS;
1387         }
1388         if($changes['std'] != 0) {
1389             $SESSION->dst_offsets[$changes['std']] = 0;
1390         }
1391     }
1392
1393     // Put in a guard element at the top
1394     $maxtimestamp = max(array_keys($SESSION->dst_offsets));
1395     $SESSION->dst_offsets[($maxtimestamp + DAYSECS)] = NULL; // DAYSECS is arbitrary, any "small" number will do
1396
1397     // Sort again
1398     krsort($SESSION->dst_offsets);
1399
1400     return true;
1401 }
1402
1403 function dst_changes_for_year($year, $timezone) {
1404
1405     if($timezone->dst_startday == 0 && $timezone->dst_weekday == 0 && $timezone->std_startday == 0 && $timezone->std_weekday == 0) {
1406         return NULL;
1407     }
1408
1409     $monthdaydst = find_day_in_month($timezone->dst_startday, $timezone->dst_weekday, $timezone->dst_month, $year);
1410     $monthdaystd = find_day_in_month($timezone->std_startday, $timezone->std_weekday, $timezone->std_month, $year);
1411
1412     list($dst_hour, $dst_min) = explode(':', $timezone->dst_time);
1413     list($std_hour, $std_min) = explode(':', $timezone->std_time);
1414
1415     $timedst = make_timestamp($year, $timezone->dst_month, $monthdaydst, 0, 0, 0, 99, false);
1416     $timestd = make_timestamp($year, $timezone->std_month, $monthdaystd, 0, 0, 0, 99, false);
1417
1418     // Instead of putting hour and minute in make_timestamp(), we add them afterwards.
1419     // This has the advantage of being able to have negative values for hour, i.e. for timezones
1420     // where GMT time would be in the PREVIOUS day than the local one on which DST changes.
1421
1422     $timedst += $dst_hour * HOURSECS + $dst_min * MINSECS;
1423     $timestd += $std_hour * HOURSECS + $std_min * MINSECS;
1424
1425     return array('dst' => $timedst, 0 => $timedst, 'std' => $timestd, 1 => $timestd);
1426 }
1427
1428 // $time must NOT be compensated at all, it has to be a pure timestamp
1429 function dst_offset_on($time) {
1430     global $SESSION;
1431
1432     if(!calculate_user_dst_table() || empty($SESSION->dst_offsets)) {
1433         return 0;
1434     }
1435
1436     reset($SESSION->dst_offsets);
1437     while(list($from, $offset) = each($SESSION->dst_offsets)) {
1438         if($from <= $time) {
1439             break;
1440         }
1441     }
1442
1443     // This is the normal return path
1444     if($offset !== NULL) {
1445         return $offset;
1446     }
1447
1448     // Reaching this point means we haven't calculated far enough, do it now:
1449     // Calculate extra DST changes if needed and recurse. The recursion always
1450     // moves toward the stopping condition, so will always end.
1451
1452     if($from == 0) {
1453         // We need a year smaller than $SESSION->dst_range[0]
1454         if($SESSION->dst_range[0] == 1971) {
1455             return 0;
1456         }
1457         calculate_user_dst_table($SESSION->dst_range[0] - 5, NULL);
1458         return dst_offset_on($time);
1459     }
1460     else {
1461         // We need a year larger than $SESSION->dst_range[1]
1462         if($SESSION->dst_range[1] == 2035) {
1463             return 0;
1464         }
1465         calculate_user_dst_table(NULL, $SESSION->dst_range[1] + 5);
1466         return dst_offset_on($time);
1467     }
1468 }
1469
1470 function find_day_in_month($startday, $weekday, $month, $year) {
1471
1472     $daysinmonth = days_in_month($month, $year);
1473
1474     if($weekday == -1) {
1475         // Don't care about weekday, so return:
1476         //    abs($startday) if $startday != -1
1477         //    $daysinmonth otherwise
1478         return ($startday == -1) ? $daysinmonth : abs($startday);
1479     }
1480
1481     // From now on we 're looking for a specific weekday
1482
1483     // Give "end of month" its actual value, since we know it
1484     if($startday == -1) {
1485         $startday = -1 * $daysinmonth;
1486     }
1487
1488     // Starting from day $startday, the sign is the direction
1489
1490     if($startday < 1) {
1491
1492         $startday = abs($startday);
1493         $lastmonthweekday  = strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year, 0));
1494
1495         // This is the last such weekday of the month
1496         $lastinmonth = $daysinmonth + $weekday - $lastmonthweekday;
1497         if($lastinmonth > $daysinmonth) {
1498             $lastinmonth -= 7;
1499         }
1500
1501         // Find the first such weekday <= $startday
1502         while($lastinmonth > $startday) {
1503             $lastinmonth -= 7;
1504         }
1505
1506         return $lastinmonth;
1507
1508     }
1509     else {
1510
1511         $indexweekday = strftime('%w', mktime(12, 0, 0, $month, $startday, $year, 0));
1512
1513         $diff = $weekday - $indexweekday;
1514         if($diff < 0) {
1515             $diff += 7;
1516         }
1517
1518         // This is the first such weekday of the month equal to or after $startday
1519         $firstfromindex = $startday + $diff;
1520
1521         return $firstfromindex;
1522
1523     }
1524 }
1525
1526 /**
1527  * Calculate the number of days in a given month
1528  *
1529  * @param int $month The month whose day count is sought
1530  * @param int $year The year of the month whose day count is sought
1531  * @return int
1532  */
1533 function days_in_month($month, $year) {
1534    return intval(date('t', mktime(12, 0, 0, $month, 1, $year, 0)));
1535 }
1536
1537 /**
1538  * Calculate the position in the week of a specific calendar day
1539  *
1540  * @param int $day The day of the date whose position in the week is sought
1541  * @param int $month The month of the date whose position in the week is sought
1542  * @param int $year The year of the date whose position in the week is sought
1543  * @return int
1544  */
1545 function dayofweek($day, $month, $year) {
1546     // I wonder if this is any different from
1547     // strftime('%w', mktime(12, 0, 0, $month, $daysinmonth, $year, 0));
1548     return intval(date('w', mktime(12, 0, 0, $month, $day, $year, 0)));
1549 }
1550
1551 /// USER AUTHENTICATION AND LOGIN ////////////////////////////////////////
1552
1553 /**
1554  * Makes sure that $USER->sesskey exists, if $USER itself exists. It sets a new sesskey
1555  * if one does not already exist, but does not overwrite existing sesskeys. Returns the
1556  * sesskey string if $USER exists, or boolean false if not.
1557  *
1558  * @uses $USER
1559  * @return string
1560  */
1561 function sesskey() {
1562     global $USER;
1563
1564     if(!isset($USER)) {
1565         return false;
1566     }
1567
1568     if (empty($USER->sesskey)) {
1569         $USER->sesskey = random_string(10);
1570     }
1571
1572     return $USER->sesskey;
1573 }
1574
1575
1576 /**
1577  * For security purposes, this function will check that the currently
1578  * given sesskey (passed as a parameter to the script or this function)
1579  * matches that of the current user.
1580  *
1581  * @param string $sesskey optionally provided sesskey
1582  * @return bool
1583  */
1584 function confirm_sesskey($sesskey=NULL) {
1585     global $USER;
1586
1587     if (!empty($USER->ignoresesskey) || !empty($CFG->ignoresesskey)) {
1588         return true;
1589     }
1590
1591     if (empty($sesskey)) {
1592         $sesskey = required_param('sesskey', PARAM_RAW);  // Check script parameters
1593     }
1594
1595     if (!isset($USER->sesskey)) {
1596         return false;
1597     }
1598
1599     return ($USER->sesskey === $sesskey);
1600 }
1601
1602 /**
1603  * Setup all global $CFG course variables, set locale and also themes
1604  * This function can be used on pages that do not require login instead of require_login()
1605  *
1606  * @param mixed $courseorid id of the course or course object
1607  */
1608 function course_setup($courseorid=0) {
1609     global $COURSE, $CFG, $SITE;
1610
1611 /// Redefine global $COURSE if needed
1612     if (empty($courseorid)) {
1613         // no change in global $COURSE - for backwards compatibiltiy
1614         // if require_rogin() used after require_login($courseid);
1615     } else if (is_object($courseorid)) {
1616         $COURSE = clone($courseorid);
1617     } else {
1618         global $course; // used here only to prevent repeated fetching from DB - may be removed later
1619         if (!empty($course->id) and $course->id == SITEID) {
1620             $COURSE = clone($SITE);
1621         } else if (!empty($course->id) and $course->id == $courseorid) {
1622             $COURSE = clone($course);
1623         } else {
1624             if (!$COURSE = get_record('course', 'id', $courseorid)) {
1625                 error('Invalid course ID');
1626             }
1627         }
1628     }
1629
1630 /// set locale and themes
1631     moodle_setlocale();
1632     theme_setup();
1633
1634 }
1635
1636 /**
1637  * This function checks that the current user is logged in and has the
1638  * required privileges
1639  *
1640  * This function checks that the current user is logged in, and optionally
1641  * whether they are allowed to be in a particular course and view a particular
1642  * course module.
1643  * If they are not logged in, then it redirects them to the site login unless
1644  * $autologinguest is set and {@link $CFG}->autologinguests is set to 1 in which
1645  * case they are automatically logged in as guests.
1646  * If $courseid is given and the user is not enrolled in that course then the
1647  * user is redirected to the course enrolment page.
1648  * If $cm is given and the coursemodule is hidden and the user is not a teacher
1649  * in the course then the user is redirected to the course home page.
1650  *
1651  * @uses $CFG
1652  * @uses $SESSION
1653  * @uses $USER
1654  * @uses $FULLME
1655  * @uses SITEID
1656  * @uses $COURSE
1657  * @param mixed $courseorid id of the course or course object
1658  * @param bool $autologinguest
1659  * @param object $cm course module object
1660  */
1661 function require_login($courseorid=0, $autologinguest=true, $cm=null) {
1662
1663     global $CFG, $SESSION, $USER, $COURSE, $FULLME;
1664
1665 /// setup global $COURSE, themes, language and locale
1666     course_setup($courseorid);
1667
1668 /// If the user is not even logged in yet then make sure they are
1669     if (!isloggedin()) {
1670         //NOTE: $USER->site check was obsoleted by session test cookie,
1671         //      $USER->confirmed test is in login/index.php
1672         $SESSION->wantsurl = $FULLME;
1673         if (!empty($_SERVER['HTTP_REFERER'])) {
1674             $SESSION->fromurl  = $_SERVER['HTTP_REFERER'];
1675         }
1676         if ($autologinguest and !empty($CFG->guestloginbutton) and !empty($CFG->autologinguests) and ($COURSE->id == SITEID or $COURSE->guest) ) {
1677             $loginguest = '?loginguest=true';
1678         } else {
1679             $loginguest = '';
1680         }
1681         if (empty($CFG->loginhttps) or $loginguest) { //do not require https for guest logins
1682             redirect($CFG->wwwroot .'/login/index.php'. $loginguest);
1683         } else {
1684             $wwwroot = str_replace('http:','https:', $CFG->wwwroot);
1685             redirect($wwwroot .'/login/index.php');
1686         }
1687         exit;
1688     }
1689
1690 /// loginas as redirection if needed
1691     if ($COURSE->id != SITEID and !empty($USER->realuser)) {
1692         if ($USER->loginascontext->contextlevel == CONTEXT_COURSE) {
1693             if ($USER->loginascontext->instanceid != $COURSE->id) {
1694                 print_error('loginasonecourse', '', $CFG->wwwroot.'/course/view.php?id='.$USER->loginascontext->instanceid);
1695             }
1696         }
1697     }
1698
1699
1700 /// check whether the user should be changing password (but only if it is REALLY them)
1701     if (get_user_preferences('auth_forcepasswordchange') && empty($USER->realuser)) {
1702         $userauth = get_auth_plugin($USER->auth);
1703         if ($userauth->can_change_password()) {
1704             $SESSION->wantsurl = $FULLME;
1705             if ($changeurl = $userauth->change_password_url()) {
1706                 //use plugin custom url
1707                 redirect($changeurl);
1708             } else {
1709                 //use moodle internal method
1710                 if (empty($CFG->loginhttps)) {
1711                     redirect($CFG->wwwroot .'/login/change_password.php');
1712                 } else {
1713                     $wwwroot = str_replace('http:','https:', $CFG->wwwroot);
1714                     redirect($wwwroot .'/login/change_password.php');
1715                 }
1716             }
1717         } else {
1718             error(get_string('nopasswordchangeforced', 'auth'));
1719         }
1720     }
1721
1722 /// Check that the user account is properly set up
1723     if (user_not_fully_set_up($USER)) {
1724         $SESSION->wantsurl = $FULLME;
1725         redirect($CFG->wwwroot .'/user/edit.php?id='. $USER->id .'&amp;course='. SITEID);
1726     }
1727
1728 /// Make sure current IP matches the one for this session (if required)
1729     if (!empty($CFG->tracksessionip)) {
1730         if ($USER->sessionIP != md5(getremoteaddr())) {
1731             error(get_string('sessionipnomatch', 'error'));
1732         }
1733     }
1734
1735 /// Make sure the USER has a sesskey set up.  Used for checking script parameters.
1736     sesskey();
1737
1738     // Check that the user has agreed to a site policy if there is one
1739     if (!empty($CFG->sitepolicy)) {
1740         if (!$USER->policyagreed) {
1741             $SESSION->wantsurl = $FULLME;
1742             redirect($CFG->wwwroot .'/user/policy.php');
1743         }
1744     }
1745
1746     // Fetch the system context, we are going to use it a lot.
1747     $sysctx = get_context_instance(CONTEXT_SYSTEM);
1748
1749 /// If the site is currently under maintenance, then print a message
1750     if (!has_capability('moodle/site:config', $sysctx)) {
1751         if (file_exists($CFG->dataroot.'/'.SITEID.'/maintenance.html')) {
1752             print_maintenance_message();
1753             exit;
1754         }
1755     }
1756
1757 /// groupmembersonly access control
1758     if (!empty($CFG->enablegroupings) and $cm and $cm->groupmembersonly and !has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id))) {
1759         if (isguestuser() or !groups_has_membership($cm)) {
1760             error(get_string('groupmembersonlyerror', 'group'), $CFG->wwwroot.'/course/view.php?id='.$cm->course);
1761         }
1762     }
1763
1764     // Fetch the course context, and prefetch its child contexts
1765     if (!isset($COURSE->context)) {
1766         if ( ! $COURSE->context = get_context_instance(CONTEXT_COURSE, $COURSE->id) ) {
1767             print_error('nocontext');
1768         }
1769     }
1770     if ($COURSE->id == SITEID) {
1771         /// Eliminate hidden site activities straight away
1772         if (!empty($cm) && !$cm->visible
1773             && !has_capability('moodle/course:viewhiddenactivities', $COURSE->context)) {
1774             redirect($CFG->wwwroot, get_string('activityiscurrentlyhidden'));
1775         }
1776         return;
1777
1778     } else {
1779
1780         /// Check if the user can be in a particular course
1781         if (empty($USER->access['rsw'][$COURSE->context->path])) {
1782             //
1783             // Spaghetti logic construct
1784             //
1785             // - able to view course?
1786             // - able to view category?
1787             // => if either is missing, course is hidden from this user
1788             //
1789             // It's carefully ordered so we run the cheap checks first, and the
1790             // more costly checks last...
1791             //
1792             if (! (($COURSE->visible || has_capability('moodle/course:viewhiddencourses', $COURSE->context))
1793                    && (course_parent_visible($COURSE)) || has_capability('moodle/course:viewhiddencourses',
1794                                                                         get_context_instance(CONTEXT_COURSECAT,
1795                                                                                              $COURSE->category)))) {
1796                 print_header_simple();
1797                 notice(get_string('coursehidden'), $CFG->wwwroot .'/');
1798             }
1799         }
1800
1801     /// Non-guests who don't currently have access, check if they can be allowed in as a guest
1802
1803         if ($USER->username != 'guest' and !has_capability('moodle/course:view', $COURSE->context)) {
1804             if ($COURSE->guest == 1) {
1805                  // Temporarily assign them guest role for this context, if it fails later user is asked to enrol
1806                  $USER->access = load_temp_role($COURSE->context, $CFG->guestroleid, $USER->access);
1807             }
1808         }
1809
1810     /// If the user is a guest then treat them according to the course policy about guests
1811
1812         if (has_capability('moodle/legacy:guest', $COURSE->context, NULL, false)) {
1813             switch ($COURSE->guest) {    /// Check course policy about guest access
1814
1815                 case 1:    /// Guests always allowed
1816                     if (!has_capability('moodle/course:view', $COURSE->context)) {    // Prohibited by capability
1817                         print_header_simple();
1818                         notice(get_string('guestsnotallowed', '', format_string($COURSE->fullname)), "$CFG->wwwroot/login/index.php");
1819                     }
1820                     if (!empty($cm) and !$cm->visible) { // Not allowed to see module, send to course page
1821                         redirect($CFG->wwwroot.'/course/view.php?id='.$cm->course,
1822                                  get_string('activityiscurrentlyhidden'));
1823                     }
1824
1825                     return;   // User is allowed to see this course
1826
1827                     break;
1828
1829                 case 2:    /// Guests allowed with key
1830                     if (!empty($USER->enrolkey[$COURSE->id])) {   // Set by enrol/manual/enrol.php
1831                         return true;
1832                     }
1833                     //  otherwise drop through to logic below (--> enrol.php)
1834                     break;
1835
1836                 default:    /// Guests not allowed
1837                     $strloggedinasguest = get_string('loggedinasguest');
1838                     print_header_simple('', '',
1839                             build_navigation(array(array('name' => $strloggedinasguest, 'link' => null, 'type' => 'misc'))));
1840                     if (empty($USER->access['rsw'][$COURSE->context->path])) {  // Normal guest
1841                         notice(get_string('guestsnotallowed', '', format_string($COURSE->fullname)), "$CFG->wwwroot/login/index.php");
1842                     } else {
1843                         notify(get_string('guestsnotallowed', '', format_string($COURSE->fullname)));
1844                         echo '<div class="notifyproblem">'.switchroles_form($COURSE->id).'</div>';
1845                         print_footer($COURSE);
1846                         exit;
1847                     }
1848                     break;
1849             }
1850
1851     /// For non-guests, check if they have course view access
1852
1853         } else if (has_capability('moodle/course:view', $COURSE->context)) {
1854             if (!empty($USER->realuser)) {   // Make sure the REAL person can also access this course
1855                 if (!has_capability('moodle/course:view', $COURSE->context, $USER->realuser)) {
1856                     print_header_simple();
1857                     notice(get_string('studentnotallowed', '', fullname($USER, true)), $CFG->wwwroot .'/');
1858                 }
1859             }
1860
1861         /// Make sure they can read this activity too, if specified
1862
1863             if (!empty($cm) and !$cm->visible and !has_capability('moodle/course:viewhiddenactivities', $COURSE->context)) {
1864                 redirect($CFG->wwwroot.'/course/view.php?id='.$cm->course, get_string('activityiscurrentlyhidden'));
1865             }
1866             return;   // User is allowed to see this course
1867
1868         }
1869
1870
1871     /// Currently not enrolled in the course, so see if they want to enrol
1872         $SESSION->wantsurl = $FULLME;
1873         redirect($CFG->wwwroot .'/course/enrol.php?id='. $COURSE->id);
1874         die;
1875     }
1876 }
1877
1878
1879
1880 /**
1881  * This function just makes sure a user is logged out.
1882  *
1883  * @uses $CFG
1884  * @uses $USER
1885  */
1886 function require_logout() {
1887
1888     global $USER, $CFG, $SESSION;
1889
1890     if (isloggedin()) {
1891         add_to_log(SITEID, "user", "logout", "view.php?id=$USER->id&course=".SITEID, $USER->id, 0, $USER->id);
1892
1893         $authsequence = get_enabled_auth_plugins(); // auths, in sequence
1894         foreach($authsequence as $authname) {
1895             $authplugin = get_auth_plugin($authname);
1896             $authplugin->prelogout_hook();
1897         }
1898     }
1899
1900     if (ini_get_bool("register_globals") and check_php_version("4.3.0")) {
1901         // This method is just to try to avoid silly warnings from PHP 4.3.0
1902         session_unregister("USER");
1903         session_unregister("SESSION");
1904     }
1905
1906     // Initialize variable to pass-by-reference to headers_sent(&$file, &$line)
1907     $file = $line = null;
1908     if (headers_sent($file, $line)) {
1909         error_log('MoodleSessionTest cookie could not be set in moodlelib.php:'.__LINE__);
1910         error_log('Headers were already sent in file: '.$file.' on line '.$line);
1911     } else {
1912         setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
1913     }
1914
1915     unset($_SESSION['USER']);
1916     unset($_SESSION['SESSION']);
1917
1918     unset($SESSION);
1919     unset($USER);
1920
1921 }
1922
1923 /**
1924  * This is a weaker version of {@link require_login()} which only requires login
1925  * when called from within a course rather than the site page, unless
1926  * the forcelogin option is turned on.
1927  *
1928  * @uses $CFG
1929  * @param mixed $courseorid The course object or id in question
1930  * @param bool $autologinguest Allow autologin guests if that is wanted
1931  * @param object $cm Course activity module if known
1932  */
1933 function require_course_login($courseorid, $autologinguest=true, $cm=null) {
1934     global $CFG;
1935     if (!empty($CFG->forcelogin)) {
1936         // login required for both SITE and courses
1937         require_login($courseorid, $autologinguest, $cm);
1938
1939     } else if (!empty($cm) and !$cm->visible) {
1940         // always login for hidden activities
1941         require_login($courseorid, $autologinguest, $cm);
1942
1943     } else if ((is_object($courseorid) and $courseorid->id == SITEID)
1944           or (!is_object($courseorid) and $courseorid == SITEID)) {
1945         //login for SITE not required
1946         return;
1947
1948     } else {
1949         // course login always required
1950         require_login($courseorid, $autologinguest, $cm);
1951     }
1952 }
1953
1954 /**
1955  * Require key login. Function terminates with error if key not found or incorrect.
1956  * @param string $script unique script identifier
1957  * @param int $instance optional instance id
1958  */
1959 function require_user_key_login($script, $instance=null) {
1960     global $nomoodlecookie, $USER, $SESSION, $CFG;
1961
1962     if (empty($nomoodlecookie)) {
1963         error('Incorrect use of require_key_login() - session cookies must be disabled!');
1964     }
1965
1966 /// extra safety
1967     @session_write_close();
1968
1969     $keyvalue = required_param('key', PARAM_ALPHANUM);
1970
1971     if (!$key = get_record('user_private_key', 'script', $script, 'value', $keyvalue, 'instance', $instance)) {
1972         error('Incorrect key');
1973     }
1974
1975     if (!empty($key->validuntil) and $key->validuntil < time()) {
1976         error('Expired key');
1977     }
1978
1979     if ($key->iprestriction) {
1980         $remoteaddr = getremoteaddr();
1981         if ($remoteaddr == '' or !address_in_subnet($remoteaddr, $key->iprestriction)) {
1982             error('Client IP address mismatch');
1983         }
1984     }
1985
1986     if (!$user = get_record('user', 'id', $key->userid)) {
1987         error('Incorrect user record');
1988     }
1989
1990 /// emulate normal session
1991     $SESSION = new object();
1992     $USER    = $user;
1993
1994 /// note we are not using normal login
1995     if (!defined('USER_KEY_LOGIN')) {
1996         define('USER_KEY_LOGIN', true);
1997     }
1998
1999     load_all_capabilities();
2000
2001 /// return isntance id - it might be empty
2002     return $key->instance;
2003 }
2004
2005 /**
2006  * Creates a new private user access key.
2007  * @param string $script unique target identifier
2008  * @param int $userid
2009  * @param instance $int optional instance id
2010  * @param string $iprestriction optional ip restricted access
2011  * @param timestamp $validuntil key valid only until given data
2012  * @return string access key value
2013  */
2014 function create_user_key($script, $userid, $instance=null, $iprestriction=null, $validuntil=null) {
2015     $key = new object();
2016     $key->script        = $script;
2017     $key->userid        = $userid;
2018     $key->instance      = $instance;
2019     $key->iprestriction = $iprestriction;
2020     $key->validuntil    = $validuntil;
2021     $key->timecreated   = time();
2022
2023     $key->value         = md5($userid.'_'.time().random_string(40)); // something long and unique
2024     while (record_exists('user_private_key', 'value', $key->value)) {
2025         // must be unique
2026         $key->value     = md5($userid.'_'.time().random_string(40));
2027     }
2028
2029     if (!insert_record('user_private_key', $key)) {
2030         error('Can not insert new key');
2031     }
2032
2033     return $key->value;
2034 }
2035
2036 /**
2037  * Modify the user table by setting the currently logged in user's
2038  * last login to now.
2039  *
2040  * @uses $USER
2041  * @return bool
2042  */
2043 function update_user_login_times() {
2044     global $USER;
2045
2046     $user = new object();
2047     $USER->lastlogin = $user->lastlogin = $USER->currentlogin;
2048     $USER->currentlogin = $user->lastaccess = $user->currentlogin = time();
2049
2050     $user->id = $USER->id;
2051
2052     return update_record('user', $user);
2053 }
2054
2055 /**
2056  * Determines if a user has completed setting up their account.
2057  *
2058  * @param user $user A {@link $USER} object to test for the existance of a valid name and email
2059  * @return bool
2060  */
2061 function user_not_fully_set_up($user) {
2062     return ($user->username != 'guest' and (empty($user->firstname) or empty($user->lastname) or empty($user->email) or over_bounce_threshold($user)));
2063 }
2064
2065 function over_bounce_threshold($user) {
2066
2067     global $CFG;
2068
2069     if (empty($CFG->handlebounces)) {
2070         return false;
2071     }
2072     // set sensible defaults
2073     if (empty($CFG->minbounces)) {
2074         $CFG->minbounces = 10;
2075     }
2076     if (empty($CFG->bounceratio)) {
2077         $CFG->bounceratio = .20;
2078     }
2079     $bouncecount = 0;
2080     $sendcount = 0;
2081     if ($bounce = get_record('user_preferences','userid',$user->id,'name','email_bounce_count')) {
2082         $bouncecount = $bounce->value;
2083     }
2084     if ($send = get_record('user_preferences','userid',$user->id,'name','email_send_count')) {
2085         $sendcount = $send->value;
2086     }
2087     return ($bouncecount >= $CFG->minbounces && $bouncecount/$sendcount >= $CFG->bounceratio);
2088 }
2089
2090 /**
2091  * @param $user - object containing an id
2092  * @param $reset - will reset the count to 0
2093  */
2094 function set_send_count($user,$reset=false) {
2095     if ($pref = get_record('user_preferences','userid',$user->id,'name','email_send_count')) {
2096         $pref->value = (!empty($reset)) ? 0 : $pref->value+1;
2097         update_record('user_preferences',$pref);
2098     }
2099     else if (!empty($reset)) { // if it's not there and we're resetting, don't bother.
2100         // make a new one
2101         $pref->name = 'email_send_count';
2102         $pref->value = 1;
2103         $pref->userid = $user->id;
2104         insert_record('user_preferences',$pref, false);
2105     }
2106 }
2107
2108 /**
2109 * @param $user - object containing an id
2110  * @param $reset - will reset the count to 0
2111  */
2112 function set_bounce_count($user,$reset=false) {
2113     if ($pref = get_record('user_preferences','userid',$user->id,'name','email_bounce_count')) {
2114         $pref->value = (!empty($reset)) ? 0 : $pref->value+1;
2115         update_record('user_preferences',$pref);
2116     }
2117     else if (!empty($reset)) { // if it's not there and we're resetting, don't bother.
2118         // make a new one
2119         $pref->name = 'email_bounce_count';
2120         $pref->value = 1;
2121         $pref->userid = $user->id;
2122         insert_record('user_preferences',$pref, false);
2123     }
2124 }
2125
2126 /**
2127  * Keeps track of login attempts
2128  *
2129  * @uses $SESSION
2130  */
2131 function update_login_count() {
2132
2133     global $SESSION;
2134
2135     $max_logins = 10;
2136
2137     if (empty($SESSION->logincount)) {
2138         $SESSION->logincount = 1;
2139     } else {
2140         $SESSION->logincount++;
2141     }
2142
2143     if ($SESSION->logincount > $max_logins) {
2144         unset($SESSION->wantsurl);
2145         error(get_string('errortoomanylogins'));
2146     }
2147 }
2148
2149 /**
2150  * Resets login attempts
2151  *
2152  * @uses $SESSION
2153  */
2154 function reset_login_count() {
2155     global $SESSION;
2156
2157     $SESSION->logincount = 0;
2158 }
2159
2160 function sync_metacourses() {
2161
2162     global $CFG;
2163
2164     if (!$courses = get_records('course', 'metacourse', 1)) {
2165         return;
2166     }
2167
2168     foreach ($courses as $course) {
2169         sync_metacourse($course);
2170     }
2171 }
2172
2173 /**
2174  * Goes through all enrolment records for the courses inside the metacourse and sync with them.
2175  *
2176  * @param mixed $course the metacourse to synch. Either the course object itself, or the courseid.
2177  */
2178 function sync_metacourse($course) {
2179     global $CFG;
2180
2181     // Check the course is valid.
2182     if (!is_object($course)) {
2183         if (!$course = get_record('course', 'id', $course)) {
2184             return false; // invalid course id
2185         }
2186     }
2187
2188     // Check that we actually have a metacourse.
2189     if (empty($course->metacourse)) {
2190         return false;
2191     }
2192
2193     // Get a list of roles that should not be synced.
2194     if (!empty($CFG->nonmetacoursesyncroleids)) {
2195         $roleexclusions = 'ra.roleid NOT IN (' . $CFG->nonmetacoursesyncroleids . ') AND';
2196     } else {
2197         $roleexclusions = '';
2198     }
2199
2200     // Get the context of the metacourse.
2201     $context = get_context_instance(CONTEXT_COURSE, $course->id); // SITEID can not be a metacourse
2202
2203     // We do not ever want to unassign the list of metacourse manager, so get a list of them.
2204     if ($users = get_users_by_capability($context, 'moodle/course:managemetacourse')) {
2205         $managers = array_keys($users);
2206     } else {
2207         $managers = array();
2208     }
2209
2210     // Get assignments of a user to a role that exist in a child course, but
2211     // not in the meta coure. That is, get a list of the assignments that need to be made.
2212     if (!$assignments = get_records_sql("
2213             SELECT
2214                 ra.id, ra.roleid, ra.userid
2215             FROM
2216                 {$CFG->prefix}role_assignments ra,
2217                 {$CFG->prefix}context con,
2218                 {$CFG->prefix}course_meta cm
2219             WHERE
2220                 ra.contextid = con.id AND
2221                 con.contextlevel = " . CONTEXT_COURSE . " AND
2222                 con.instanceid = cm.child_course AND
2223                 cm.parent_course = {$course->id} AND
2224                 $roleexclusions
2225                 NOT EXISTS (
2226                     SELECT 1 FROM
2227                         {$CFG->prefix}role_assignments ra2
2228                     WHERE
2229                         ra2.userid = ra.userid AND
2230                         ra2.roleid = ra.roleid AND
2231                         ra2.contextid = {$context->id}
2232                 )
2233     ")) {
2234         $assignments = array();
2235     }
2236
2237     // Get assignments of a user to a role that exist in the meta course, but
2238     // not in any child courses. That is, get a list of the unassignments that need to be made.
2239     if (!$unassignments = get_records_sql("
2240             SELECT
2241                 ra.id, ra.roleid, ra.userid
2242             FROM
2243                 {$CFG->prefix}role_assignments ra
2244             WHERE
2245                 ra.contextid = {$context->id} AND
2246                 $roleexclusions
2247                 NOT EXISTS (
2248                     SELECT 1 FROM
2249                         {$CFG->prefix}role_assignments ra2,
2250                         {$CFG->prefix}context con2,
2251                         {$CFG->prefix}course_meta cm
2252                     WHERE
2253                         ra2.userid = ra.userid AND
2254                         ra2.roleid = ra.roleid AND
2255                         ra2.contextid = con2.id AND
2256                         con2.contextlevel = " . CONTEXT_COURSE . " AND
2257                         con2.instanceid = cm.child_course AND
2258                         cm.parent_course = {$course->id}
2259                 )
2260     ")) {
2261         $unassignments = array();
2262     }
2263
2264     $success = true;
2265
2266     // Make the unassignments, if they are not managers.
2267     $unchanged = true;
2268     foreach ($unassignments as $unassignment) {
2269         if (!in_array($unassignment->userid, $managers)) {
2270             $success = role_unassign($unassignment->roleid, $unassignment->userid, 0, $context->id) && $success;
2271             $unchanged = false;
2272         }
2273     }
2274
2275     // Make the assignments.
2276     foreach ($assignments as $assignment) {
2277         $success = role_assign($assignment->roleid, $assignment->userid, 0, $context->id) && $success;
2278         $unchanged = false;
2279     }
2280     if (!$unchanged) {
2281         // force accessinfo refresh for users visiting this context...
2282         mark_context_dirty($context->path);
2283     }
2284
2285     return $success;
2286
2287 // TODO: finish timeend and timestart
2288 // maybe we could rely on cron job to do the cleaning from time to time
2289 }
2290
2291 /**
2292  * Adds a record to the metacourse table and calls sync_metacoures
2293  */
2294 function add_to_metacourse ($metacourseid, $courseid) {
2295
2296     if (!$metacourse = get_record("course","id",$metacourseid)) {
2297         return false;
2298     }
2299
2300     if (!$course = get_record("course","id",$courseid)) {
2301         return false;
2302     }
2303
2304     if (!$record = get_record("course_meta","parent_course",$metacourseid,"child_course",$courseid)) {
2305         $rec = new object();
2306         $rec->parent_course = $metacourseid;
2307         $rec->child_course = $courseid;
2308         if (!insert_record('course_meta',$rec)) {
2309             return false;
2310         }
2311         return sync_metacourse($metacourseid);
2312     }
2313     return true;
2314
2315 }
2316
2317 /**
2318  * Removes the record from the metacourse table and calls sync_metacourse
2319  */
2320 function remove_from_metacourse($metacourseid, $courseid) {
2321
2322     if (delete_records('course_meta','parent_course',$metacourseid,'child_course',$courseid)) {
2323         return sync_metacourse($metacourseid);
2324     }
2325     return false;
2326 }
2327
2328
2329 /**
2330  * Determines if a user is currently logged in
2331  *
2332  * @uses $USER
2333  * @return bool
2334  */
2335 function isloggedin() {
2336     global $USER;
2337
2338     return (!empty($USER->id));
2339 }
2340
2341 /**
2342  * Determines if a user is logged in as real guest user with username 'guest'.
2343  * This function is similar to original isguest() in 1.6 and earlier.
2344  * Current isguest() is deprecated - do not use it anymore.
2345  *
2346  * @param $user mixed user object or id, $USER if not specified
2347  * @return bool true if user is the real guest user, false if not logged in or other user
2348  */
2349 function isguestuser($user=NULL) {
2350     global $USER;
2351     if ($user === NULL) {
2352         $user = $USER;
2353     } else if (is_numeric($user)) {
2354         $user = get_record('user', 'id', $user, '', '', '', '', 'id, username');
2355     }
2356
2357     if (empty($user->id)) {
2358         return false; // not logged in, can not be guest
2359     }
2360
2361     return ($user->username == 'guest');
2362 }
2363
2364 /**
2365  * Determines if the currently logged in user is in editing mode.
2366  * Note: originally this function had $userid parameter - it was not usable anyway
2367  *
2368  * @uses $USER, $PAGE
2369  * @return bool
2370  */
2371 function isediting() {
2372     global $USER, $PAGE;
2373
2374     if (empty($USER->editing)) {
2375         return false;
2376     } elseif (is_object($PAGE) && method_exists($PAGE,'user_allowed_editing')) {
2377         return $PAGE->user_allowed_editing();
2378     }
2379     return true;//false;
2380 }
2381
2382 /**
2383  * Determines if the logged in user is currently moving an activity
2384  *
2385  * @uses $USER
2386  * @param int $courseid The id of the course being tested
2387  * @return bool
2388  */
2389 function ismoving($courseid) {
2390     global $USER;
2391
2392     if (!empty($USER->activitycopy)) {
2393         return ($USER->activitycopycourse == $courseid);
2394     }
2395     return false;
2396 }
2397
2398 /**
2399  * Given an object containing firstname and lastname
2400  * values, this function returns a string with the
2401  * full name of the person.
2402  * The result may depend on system settings
2403  * or language.  'override' will force both names
2404  * to be used even if system settings specify one.
2405  *
2406  * @uses $CFG
2407  * @uses $SESSION
2408  * @param object $user A {@link $USER} object to get full name of
2409  * @param bool $override If true then the name will be first name followed by last name rather than adhering to fullnamedisplay setting.
2410  */
2411 function fullname($user, $override=false) {
2412
2413     global $CFG, $SESSION;
2414
2415     if (!isset($user->firstname) and !isset($user->lastname)) {
2416         return '';
2417     }
2418
2419     if (!$override) {
2420         if (!empty($CFG->forcefirstname)) {
2421             $user->firstname = $CFG->forcefirstname;
2422         }
2423         if (!empty($CFG->forcelastname)) {
2424             $user->lastname = $CFG->forcelastname;
2425         }
2426     }
2427
2428     if (!empty($SESSION->fullnamedisplay)) {
2429         $CFG->fullnamedisplay = $SESSION->fullnamedisplay;
2430     }
2431
2432     if ($CFG->fullnamedisplay == 'firstname lastname') {
2433         return $user->firstname .' '. $user->lastname;
2434
2435     } else if ($CFG->fullnamedisplay == 'lastname firstname') {
2436         return $user->lastname .' '. $user->firstname;
2437
2438     } else if ($CFG->fullnamedisplay == 'firstname') {
2439         if ($override) {
2440             return get_string('fullnamedisplay', '', $user);
2441         } else {
2442             return $user->firstname;
2443         }
2444     }
2445
2446     return get_string('fullnamedisplay', '', $user);
2447 }
2448
2449 /**
2450  * Sets a moodle cookie with an encrypted string
2451  *
2452  * @uses $CFG
2453  * @uses DAYSECS
2454  * @uses HOURSECS
2455  * @param string $thing The string to encrypt and place in a cookie
2456  */
2457 function set_moodle_cookie($thing) {
2458     global $CFG;
2459
2460     if ($thing == 'guest') {  // Ignore guest account
2461         return;
2462     }
2463
2464     $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
2465
2466     $days = 60;
2467     $seconds = DAYSECS*$days;
2468
2469     setCookie($cookiename, '', time() - HOURSECS, '/');
2470     setCookie($cookiename, rc4encrypt($thing), time()+$seconds, '/');
2471 }
2472
2473 /**
2474  * Gets a moodle cookie with an encrypted string
2475  *
2476  * @uses $CFG
2477  * @return string
2478  */
2479 function get_moodle_cookie() {
2480     global $CFG;
2481
2482     $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
2483
2484     if (empty($_COOKIE[$cookiename])) {
2485         return '';
2486     } else {
2487         $thing = rc4decrypt($_COOKIE[$cookiename]);
2488         return ($thing == 'guest') ? '': $thing;  // Ignore guest account
2489     }
2490 }
2491
2492 /**
2493  * Returns whether a given authentication plugin exists.
2494  *
2495  * @uses $CFG
2496  * @param string $auth Form of authentication to check for. Defaults to the
2497  *        global setting in {@link $CFG}.
2498  * @return boolean Whether the plugin is available.
2499  */
2500 function exists_auth_plugin($auth) {
2501     global $CFG;
2502
2503     if (file_exists("{$CFG->dirroot}/auth/$auth/auth.php")) {
2504         return is_readable("{$CFG->dirroot}/auth/$auth/auth.php");
2505     }
2506     return false;
2507 }
2508
2509 /**
2510  * Checks if a given plugin is in the list of enabled authentication plugins.
2511  *
2512  * @param string $auth Authentication plugin.
2513  * @return boolean Whether the plugin is enabled.
2514  */
2515 function is_enabled_auth($auth) {
2516     if (empty($auth)) {
2517         return false;
2518     }
2519
2520     $enabled = get_enabled_auth_plugins();
2521
2522     return in_array($auth, $enabled);
2523 }
2524
2525 /**
2526  * Returns an authentication plugin instance.
2527  *
2528  * @uses $CFG
2529  * @param string $auth name of authentication plugin
2530  * @return object An instance of the required authentication plugin.
2531  */
2532 function get_auth_plugin($auth) {
2533     global $CFG;
2534
2535     // check the plugin exists first
2536     if (! exists_auth_plugin($auth)) {
2537         error("Authentication plugin '$auth' not found.");
2538     }
2539
2540     // return auth plugin instance
2541     require_once "{$CFG->dirroot}/auth/$auth/auth.php";
2542     $class = "auth_plugin_$auth";
2543     return new $class;
2544 }
2545
2546 /**
2547  * Returns array of active auth plugins.
2548  *
2549  * @param bool $fix fix $CFG->auth if needed
2550  * @return array
2551  */
2552 function get_enabled_auth_plugins($fix=false) {
2553     global $CFG;
2554
2555     $default = array('manual', 'nologin');
2556
2557     if (empty($CFG->auth)) {
2558         $auths = array();
2559     } else {
2560         $auths = explode(',', $CFG->auth);
2561     }
2562
2563     if ($fix) {
2564         $auths = array_unique($auths);
2565         foreach($auths as $k=>$authname) {
2566             if (!exists_auth_plugin($authname) or in_array($authname, $default)) {
2567                 unset($auths[$k]);
2568             }
2569         }
2570         $newconfig = implode(',', $auths);
2571         if (!isset($CFG->auth) or $newconfig != $CFG->auth) {
2572             set_config('auth', $newconfig);
2573         }
2574     }
2575
2576     return (array_merge($default, $auths));
2577 }
2578
2579 /**
2580  * Returns true if an internal authentication method is being used.
2581  * if method not specified then, global default is assumed
2582  *
2583  * @uses $CFG
2584  * @param string $auth Form of authentication required
2585  * @return bool
2586  */
2587 function is_internal_auth($auth) {
2588     $authplugin = get_auth_plugin($auth); // throws error if bad $auth
2589     return $authplugin->is_internal();
2590 }
2591
2592 /**
2593  * Returns an array of user fields
2594  *
2595  * @uses $CFG
2596  * @uses $db
2597  * @return array User field/column names
2598  */
2599 function get_user_fieldnames() {
2600
2601     global $CFG, $db;
2602
2603     $fieldarray = $db->MetaColumnNames($CFG->prefix.'user');
2604     unset($fieldarray['ID']);
2605
2606     return $fieldarray;
2607 }
2608
2609 /**
2610  * Creates the default "guest" user. Used both from
2611  * admin/index.php and login/index.php
2612  * @return mixed user object created or boolean false if the creation has failed
2613  */
2614 function create_guest_record() {
2615
2616     global $CFG;
2617
2618     $guest = new stdClass();
2619     $guest->auth        = 'manual';
2620     $guest->username    = 'guest';
2621     $guest->password    = hash_internal_user_password('guest');
2622     $guest->firstname   = addslashes(get_string('guestuser'));
2623     $guest->lastname    = ' ';
2624     $guest->email       = 'root@localhost';
2625     $guest->description = addslashes(get_string('guestuserinfo'));
2626     $guest->mnethostid  = $CFG->mnet_localhost_id;
2627     $guest->confirmed   = 1;
2628     $guest->lang        = $CFG->lang;
2629     $guest->timemodified= time();
2630
2631     if (! $guest->id = insert_record("user", $guest)) {
2632         return false;
2633     }
2634
2635     return $guest;
2636 }
2637
2638 /**
2639  * Creates a bare-bones user record
2640  *
2641  * @uses $CFG
2642  * @param string $username New user's username to add to record
2643  * @param string $password New user's password to add to record
2644  * @param string $auth Form of authentication required
2645  * @return object A {@link $USER} object
2646  * @todo Outline auth types and provide code example
2647  */
2648 function create_user_record($username, $password, $auth='manual') {
2649     global $CFG;
2650
2651     //just in case check text case
2652     $username = trim(moodle_strtolower($username));
2653
2654     $authplugin = get_auth_plugin($auth);
2655
2656     if ($newinfo = $authplugin->get_userinfo($username)) {
2657         $newinfo = truncate_userinfo($newinfo);
2658         foreach ($newinfo as $key => $value){
2659             $newuser->$key = addslashes($value);
2660         }
2661     }
2662
2663     if (!empty($newuser->email)) {
2664         if (email_is_not_allowed($newuser->email)) {
2665             unset($newuser->email);
2666         }
2667     }
2668
2669     $newuser->auth = $auth;
2670     $newuser->username = $username;
2671
2672     // fix for MDL-8480
2673     // user CFG lang for user if $newuser->lang is empty
2674     // or $user->lang is not an installed language
2675     $sitelangs = array_keys(get_list_of_languages());
2676     if (empty($newuser->lang) || !in_array($newuser->lang, $sitelangs)) {
2677         $newuser -> lang = $CFG->lang;
2678     }
2679     $newuser->confirmed = 1;
2680     $newuser->lastip = getremoteaddr();
2681     $newuser->timemodified = time();
2682     $newuser->mnethostid = $CFG->mnet_localhost_id;
2683
2684     if (insert_record('user', $newuser)) {
2685         $user = get_complete_user_data('username', $newuser->username);
2686         if(!empty($CFG->{'auth_'.$newuser->auth.'_forcechangepassword'})){
2687             set_user_preference('auth_forcepasswordchange', 1, $user->id);
2688         }
2689         update_internal_user_password($user, $password);
2690         return $user;
2691     }
2692     return false;
2693 }
2694
2695 /**
2696  * Will update a local user record from an external source
2697  *
2698  * @uses $CFG
2699  * @param string $username New user's username to add to record
2700  * @return user A {@link $USER} object
2701  */
2702 function update_user_record($username, $authplugin) {
2703     $username = trim(moodle_strtolower($username)); /// just in case check text case
2704
2705     $oldinfo = get_record('user', 'username', $username, '','','','', 'username, auth');
2706     $userauth = get_auth_plugin($oldinfo->auth);
2707
2708     if ($newinfo = $userauth->get_userinfo($username)) {
2709         $newinfo = truncate_userinfo($newinfo);
2710         foreach ($newinfo as $key => $value){
2711             $confkey = 'field_updatelocal_' . $key;
2712             if (!empty($userauth->config->$confkey) and $userauth->config->$confkey === 'onlogin') {
2713                 $value = addslashes(stripslashes($value));   // Just in case
2714                 set_field('user', $key, $value, 'username', $username)
2715                     or error_log("Error updating $key for $username");
2716             }
2717         }
2718     }
2719
2720     return get_complete_user_data('username', $username);
2721 }
2722
2723 function truncate_userinfo($info) {
2724 /// will truncate userinfo as it comes from auth_get_userinfo (from external auth)
2725 /// which may have large fields
2726
2727     // define the limits
2728     $limit = array(
2729                     'username'    => 100,
2730                     'idnumber'    =>  64,
2731                     'firstname'   => 100,
2732                     'lastname'    => 100,
2733                     'email'       => 100,
2734                     'icq'         =>  15,
2735                     'phone1'      =>  20,
2736                     'phone2'      =>  20,
2737                     'institution' =>  40,
2738                     'department'  =>  30,
2739                     'address'     =>  70,
2740                     'city'        =>  20,
2741                     'country'     =>   2,
2742                     'url'         => 255,
2743                     );
2744
2745     // apply where needed
2746     foreach (array_keys($info) as $key) {
2747         if (!empty($limit[$key])) {
2748             $info[$key] = trim(substr($info[$key],0, $limit[$key]));
2749         }
2750     }
2751
2752     return $info;
2753 }
2754
2755 /**
2756  * Marks user deleted in internal user database and notifies the auth plugin.
2757  * Also unenrols user from all roles and does other cleanup.
2758  * @param object $user       Userobject before delete    (without system magic quotes)
2759  * @return boolean success
2760  */
2761 function delete_user($user) {
2762     global $CFG;
2763     require_once($CFG->libdir.'/grouplib.php');
2764
2765     begin_sql();
2766
2767     // delete all grades - backup is kept in grade_grades_history table
2768     if ($grades = grade_grade::fetch_all(array('userid'=>$user->id))) {
2769         foreach ($grades as $grade) {
2770             $grade->delete('userdelete');
2771         }
2772     }
2773
2774     // remove from all groups
2775     delete_records('groups_members', 'userid', $user->id);
2776
2777     // unenrol from all roles in all contexts
2778     role_unassign(0, $user->id); // this might be slow but it is really needed - modules might do some extra cleanup!
2779
2780     // now do a final accesslib cleanup - removes all role assingments in user context and context itself
2781     delete_context(CONTEXT_USER, $user->id);
2782
2783     // mark internal user record as "deleted"
2784     $updateuser = new object();
2785     $updateuser->id           = $user->id;
2786     $updateuser->deleted      = 1;
2787     $updateuser->username     = addslashes("$user->email.".time());  // Remember it just in case
2788     $updateuser->email        = '';               // Clear this field to free it up
2789     $updateuser->idnumber     = '';               // Clear this field to free it up
2790     $updateuser->timemodified = time();
2791
2792     if (update_record('user', $updateuser)) {
2793         commit_sql();
2794         // notify auth plugin - do not block the delete even when plugin fails
2795         $authplugin = get_auth_plugin($user->auth);
2796         $authplugin->user_delete($user);
2797         return true;
2798
2799     } else {
2800         rollback_sql();
2801         return false;
2802     }
2803 }
2804
2805 /**
2806  * Retrieve the guest user object
2807  *
2808  * @uses $CFG
2809  * @return user A {@link $USER} object
2810  */
2811 function guest_user() {
2812     global $CFG;
2813
2814     if ($newuser = get_record('user', 'username', 'guest', 'mnethostid',  $CFG->mnet_localhost_id)) {
2815         $newuser->confirmed = 1;
2816         $newuser->lang = $CFG->lang;
2817         $newuser->lastip = getremoteaddr();
2818     }
2819
2820     return $newuser;
2821 }
2822
2823 /**
2824  * Given a username and password, this function looks them
2825  * up using the currently selected authentication mechanism,
2826  * and if the authentication is successful, it returns a
2827  * valid $user object from the 'user' table.
2828  *
2829  * Uses auth_ functions from the currently active auth module
2830  *
2831  * @uses $CFG
2832  * @param string $username  User's username (with system magic quotes)
2833  * @param string $password  User's password (with system magic quotes)
2834  * @return user|flase A {@link $USER} object or false if error
2835  */
2836 function authenticate_user_login($username, $password) {
2837
2838     global $CFG;
2839
2840     $authsenabled = get_enabled_auth_plugins();
2841
2842     if ($user = get_complete_user_data('username', $username)) {
2843         $auth = empty($user->auth) ? 'manual' : $user->auth;  // use manual if auth not set
2844         if ($auth=='nologin' or !is_enabled_auth($auth)) {
2845             add_to_log(0, 'login', 'error', 'index.php', $username);
2846             error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Disabled Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2847             return false;
2848         }
2849         if (!empty($user->deleted)) {
2850             add_to_log(0, 'login', 'error', 'index.php', $username);
2851             error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Deleted Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2852             return false;
2853         }
2854         $auths = array($auth);
2855
2856     } else {
2857         $auths = $authsenabled;
2858         $user = new object();
2859         $user->id = 0;     // User does not exist
2860     }
2861
2862     foreach ($auths as $auth) {
2863         $authplugin = get_auth_plugin($auth);
2864
2865         // on auth fail fall through to the next plugin
2866         if (!$authplugin->user_login($username, $password)) {
2867             continue;
2868         }
2869
2870         // successful authentication
2871         if ($user->id) {                          // User already exists in database
2872             if (empty($user->auth)) {             // For some reason auth isn't set yet
2873                 set_field('user', 'auth', $auth, 'username', $username);
2874                 $user->auth = $auth;
2875             }
2876
2877             update_internal_user_password($user, $password); // just in case salt or encoding were changed (magic quotes too one day)
2878
2879             if (!$authplugin->is_internal()) {            // update user record from external DB
2880                 $user = update_user_record($username, get_auth_plugin($user->auth));
2881             }
2882         } else {
2883             // if user not found, create him
2884             $user = create_user_record($username, $password, $auth);
2885         }
2886
2887         $authplugin->sync_roles($user);
2888
2889         foreach ($authsenabled as $hau) {
2890             $hauth = get_auth_plugin($hau);
2891             $hauth->user_authenticated_hook($user, $username, $password);
2892         }
2893
2894     /// Log in to a second system if necessary
2895     /// NOTICE: /sso/ will be moved to auth and deprecated soon; use user_authenticated_hook() instead
2896         if (!empty($CFG->sso)) {
2897             include_once($CFG->dirroot .'/sso/'. $CFG->sso .'/lib.php');
2898             if (function_exists('sso_user_login')) {
2899                 if (!sso_user_login($username, $password)) {   // Perform the signon process
2900                     notify('Second sign-on failed');
2901                 }
2902             }
2903         }
2904
2905         return $user;
2906
2907     }
2908
2909     // failed if all the plugins have failed
2910     add_to_log(0, 'login', 'error', 'index.php', $username);
2911     error_log('[client '.$_SERVER['REMOTE_ADDR']."]  $CFG->wwwroot  Failed Login:  $username  ".$_SERVER['HTTP_USER_AGENT']);
2912     return false;
2913 }
2914
2915 /**
2916  * Compare password against hash stored in internal user table.
2917  * If necessary it also updates the stored hash to new format.
2918  *
2919  * @param object user
2920  * @param string plain text password
2921  * @return bool is password valid?
2922  */
2923 function validate_internal_user_password(&$user, $password) {
2924     global $CFG;
2925
2926     if (!isset($CFG->passwordsaltmain)) {
2927         $CFG->passwordsaltmain = '';
2928     }
2929
2930     $validated = false;
2931
2932     // get password original encoding in case it was not updated to unicode yet
2933     $textlib = textlib_get_instance();
2934     $convpassword = $textlib->convert($password, 'utf-8', get_string('oldcharset'));
2935
2936     if ($user->password == md5($password.$CFG->passwordsaltmain) or $user->password == md5($password)
2937         or $user->password == md5($convpassword.$CFG->passwordsaltmain) or $user->password == md5($convpassword)) {
2938         $validated = true;
2939     } else {
2940         for ($i=1; $i<=20; $i++) { //20 alternative salts should be enough, right?
2941             $alt = 'passwordsaltalt'.$i;
2942             if (!empty($CFG->$alt)) {
2943                 if ($user->password == md5($password.$CFG->$alt) or $user->password == md5($convpassword.$CFG->$alt)) {
2944                     $validated = true;
2945                     break;
2946                 }
2947             }
2948         }
2949     }
2950
2951     if ($validated) {
2952         // force update of password hash using latest main password salt and encoding if needed
2953         update_internal_user_password($user, $password);
2954     }
2955
2956     return $validated;
2957 }
2958
2959 /**
2960  * Calculate hashed value from password using current hash mechanism.
2961  *
2962  * @param string password
2963  * @return string password hash
2964  */
2965 function hash_internal_user_password($password) {
2966     global $CFG;
2967
2968     if (isset($CFG->passwordsaltmain)) {
2969         return md5($password.$CFG->passwordsaltmain);
2970     } else {
2971         return md5($password);
2972     }
2973 }
2974
2975 /**
2976  * Update pssword hash in user object.
2977  *
2978  * @param object user
2979  * @param string plain text password
2980  * @param bool store changes also in db, default true
2981  * @return true if hash changed
2982  */
2983 function update_internal_user_password(&$user, $password) {
2984     global $CFG;
2985
2986     $authplugin = get_auth_plugin($user->auth);
2987     if (!empty($authplugin->config->preventpassindb)) {
2988         $hashedpassword = 'not cached';
2989     } else {
2990         $hashedpassword = hash_internal_user_password($password);
2991     }
2992
2993     return set_field('user', 'password',  $hashedpassword, 'id', $user->id);
2994 }
2995
2996 /**
2997  * Get a complete user record, which includes all the info
2998  * in the user record
2999  * Intended for setting as $USER session variable
3000  *
3001  * @uses $CFG
3002  * @uses SITEID
3003  * @param string $field The user field to be checked for a given value.
3004  * @param string $value The value to match for $field.
3005  * @return user A {@link $USER} object.
3006  */
3007 function get_complete_user_data($field, $value, $mnethostid=null) {
3008
3009     global $CFG;
3010
3011     if (!$field || !$value) {
3012         return false;
3013     }
3014
3015 /// Build the WHERE clause for an SQL query
3016
3017     $constraints = $field .' = \''. $value .'\' AND deleted <> \'1\'';
3018
3019     if (is_null($mnethostid)) {
3020         // if null, we restrict to local users
3021         // ** testing for local user can be done with
3022         //    mnethostid = $CFG->mnet_localhost_id
3023         //    or with
3024         //    auth != 'mnet'
3025         //    but the first one is FAST with our indexes
3026         $mnethostid = $CFG->mnet_localhost_id;
3027     }
3028     $mnethostid = (int)$mnethostid;
3029     $constraints .= ' AND mnethostid = \''.$mnethostid.'\'';
3030
3031 /// Get all the basic user data
3032
3033     if (! $user = get_record_select('user', $constraints)) {
3034         return false;
3035     }
3036
3037 /// Get various settings and preferences
3038
3039     if ($displays = get_records('course_display', 'userid', $user->id)) {
3040         foreach ($displays as $display) {
3041             $user->display[$display->course] = $display->display;
3042         }
3043     }
3044
3045     $user->preference = get_user_preferences(null, null, $user->id);
3046
3047     if ($lastaccesses = get_records('user_lastaccess', 'userid', $user->id)) {
3048         foreach ($lastaccesses as $lastaccess) {
3049             $user->lastcourseaccess[$lastaccess->courseid] = $lastaccess->timeaccess;
3050         }
3051     }
3052
3053     $sql = "SELECT g.id, g.courseid
3054               FROM {$CFG->prefix}groups g, {$CFG->prefix}groups_members gm
3055              WHERE gm.groupid=g.id AND gm.userid={$user->id}";
3056
3057     // this is a special hack to speedup calendar display
3058     $user->groupmember = array();
3059     if ($groups = get_records_sql($sql)) {
3060         foreach ($groups as $group) {
3061             if (!array_key_exists($group->courseid, $user->groupmember)) {
3062                 $user->groupmember[$group->courseid] = array();
3063             }
3064             $user->groupmember[$group->courseid][$group->id] = $group->id;
3065         }
3066     }
3067
3068 /// Rewrite some variables if necessary
3069     if (!empty($user->description)) {
3070         $user->description = true;   // No need to cart all of it around
3071     }
3072     if ($user->username == 'guest') {
3073         $user->lang       = $CFG->lang;               // Guest language always same as site
3074         $user->firstname  = get_string('guestuser');  // Name always in current language
3075         $user->lastname   = ' ';
3076     }
3077
3078     $user->sesskey  = random_string(10);
3079     $user->sessionIP = md5(getremoteaddr());   // Store the current IP in the session
3080
3081     return $user;
3082 }
3083
3084 /**
3085  * @uses $CFG
3086  * @param string $password the password to be checked agains the password policy
3087  * @param string $errmsg the error message to display when the password doesn't comply with the policy.
3088  * @return bool true if the password is valid according to the policy. false otherwise.
3089  */
3090 function check_password_policy($password, &$errmsg) {
3091     global $CFG;
3092
3093     if (empty($CFG->passwordpolicy)) {
3094         return true;
3095     }
3096
3097     $textlib = textlib_get_instance();
3098     $errmsg = '';
3099     if ($textlib->strlen($password) < $CFG->minpasswordlength) {
3100         $errmsg = get_string('errorminpasswordlength', 'auth', $CFG->minpasswordlength);
3101
3102     } else if (preg_match_all('/[[:digit:]]/u', $password, $matches) < $CFG->minpassworddigits) {
3103         $errmsg = get_string('errorminpassworddigits', 'auth', $CFG->minpassworddigits);
3104
3105     } else if (preg_match_all('/[[:lower:]]/u', $password, $matches) < $CFG->minpasswordlower) {
3106         $errmsg = get_string('errorminpasswordlower', 'auth', $CFG->minpasswordlower);
3107
3108     } else if (preg_match_all('/[[:upper:]]/u', $password, $matches) < $CFG->minpasswordupper) {
3109         $errmsg = get_string('errorminpasswordupper', 'auth', $CFG->minpasswordupper);
3110
3111     } else if (preg_match_all('/[^[:upper:][:lower:][:digit:]]/u', $password, $matches) < $CFG->minpasswordnonalphanum) {
3112         $errmsg = get_string('errorminpasswordnonalphanum', 'auth', $CFG->minpasswordnonalphanum);
3113
3114     } else if ($password == 'admin' or $password == 'password') {
3115         $errmsg = get_string('unsafepassword');
3116     }
3117
3118     if ($errmsg == '') {
3119         return true;
3120     } else {
3121         return false;
3122     }
3123 }
3124
3125
3126 /**
3127  * When logging in, this function is run to set certain preferences
3128  * for the current SESSION
3129  */
3130 function set_login_session_preferences() {
3131     global $SESSION, $CFG;
3132
3133     $SESSION->justloggedin = true;
3134
3135     unset($SESSION->lang);
3136
3137     // Restore the calendar filters, if saved
3138     if (intval(get_user_preferences('calendar_persistflt', 0))) {
3139         include_once($CFG->dirroot.'/calendar/lib.php');
3140         calendar_set_filters_status(get_user_preferences('calendav_savedflt', 0xff));
3141     }
3142 }
3143
3144
3145 /**
3146  * Delete a course, including all related data from the database,
3147  * and any associated files from the moodledata folder.
3148  *
3149  * @param int $courseid The id of the course to delete.
3150  * @param bool $showfeedback Whether to display notifications of each action the function performs.
3151  * @return bool true if all the removals succeeded. false if there were any failures. If this
3152  *             method returns false, some of the removals will probably have succeeded, and others
3153  *             failed, but you have no way of knowing which.
3154  */
3155 function delete_course($courseid, $showfeedback = true) {
3156     global $CFG;
3157     require_once($CFG->libdir.'/gradelib.php');
3158     $result = true;
3159
3160     if (!remove_course_contents($courseid, $showfeedback)) {
3161         if ($showfeedback) {
3162             notify("An error occurred while deleting some of the course contents.");
3163         }
3164         $result = false;
3165     }
3166
3167     remove_course_grades($courseid, $showfeedback);
3168
3169     if (!delete_records("course", "id", $courseid)) {
3170         if ($showfeedback) {
3171             notify("An error occurred while deleting the main course record.");
3172         }
3173         $result = false;
3174     }
3175
3176     if (!delete_records('context', 'contextlevel', CONTEXT_COURSE, 'instanceid', $courseid)) {
3177         if ($showfeedback) {
3178             notify("An error occurred while deleting the main context record.");
3179         }
3180         $result = false;
3181     }
3182
3183     if (!fulldelete($CFG->dataroot.'/'.$courseid)) {
3184         if ($showfeedback) {
3185             notify("An error occurred while deleting the course files.");
3186         }
3187         $result = false;
3188     }
3189
3190     return $result;
3191 }
3192
3193 /**
3194  * Clear a course out completely, deleting all content
3195  * but don't delete the course itself
3196  *
3197  * @uses $CFG
3198  * @param int $courseid The id of the course that is being deleted
3199  * @param bool $showfeedback Whether to display notifications of each action the function performs.
3200  * @return bool true if all the removals succeeded. false if there were any failures. If this
3201  *             method returns false, some of the removals will probably have succeeded, and others
3202  *             failed, but you have no way of knowing which.
3203  */
3204 function remove_course_contents($courseid, $showfeedback=true) {
3205
3206     global $CFG;
3207     include_once($CFG->libdir.'/questionlib.php');
3208
3209     $result = true;
3210
3211     if (! $course = get_record('course', 'id', $courseid)) {
3212         error('Course ID was incorrect (can\'t find it)');
3213     }
3214
3215     $strdeleted = get_string('deleted');
3216
3217 /// First delete every instance of every module
3218
3219     if ($allmods = get_records('modules') ) {
3220         foreach ($allmods as $mod) {
3221             $modname = $mod->name;
3222             $modfile = $CFG->dirroot .'/mod/'. $modname .'/lib.php';
3223             $moddelete = $modname .'_delete_instance';       // Delete everything connected to an instance
3224             $moddeletecourse = $modname .'_delete_course';   // Delete other stray stuff (uncommon)
3225             $count=0;
3226             if (file_exists($modfile)) {
3227                 include_once($modfile);
3228                 if (function_exists($moddelete)) {
3229                     if ($instances = get_records($modname, 'course', $course->id)) {
3230                         foreach ($instances as $instance) {
3231                             if ($cm = get_coursemodule_from_instance($modname, $instance->id, $course->id)) {
3232                                 /// Delete activity context questions and question categories
3233                                 question_delete_activity($cm,  $showfeedback);
3234                                 delete_context(CONTEXT_MODULE, $cm->id);
3235                             }
3236                             if ($moddelete($instance->id)) {
3237                                 $count++;
3238
3239                             } else {
3240                                 notify('Could not delete '. $modname .' instance '. $instance->id .' ('. format_string($instance->name) .')');
3241                                 $result = false;
3242                             }
3243                         }
3244                     }
3245                 } else {
3246                     notify('Function '. $moddelete() .'doesn\'t exist!');
3247                     $result = false;
3248                 }
3249
3250                 if (function_exists($moddeletecourse)) {
3251                     $moddeletecourse($course, $showfeedback);
3252                 }
3253             }
3254             if ($showfeedback) {
3255                 notify($strdeleted .' '. $count .' x '. $modname);
3256             }
3257         }
3258     } else {
3259         error('No modules are installed!');
3260     }
3261
3262 /// Give local code a chance to delete its references to this course.
3263     require_once('locallib.php');
3264     notify_local_delete_course($courseid, $showfeedback);
3265
3266 /// Delete course blocks
3267
3268     if ($blocks = get_records_sql("SELECT *
3269                                    FROM {$CFG->prefix}block_instance
3270                                    WHERE pagetype = '".PAGE_COURSE_VIEW."'
3271                                    AND pageid = $course->id")) {
3272         if (delete_records('block_instance', 'pagetype', PAGE_COURSE_VIEW, 'pageid', $course->id)) {
3273             if ($showfeedback) {
3274                 notify($strdeleted .' block_instance');
3275             }
3276
3277             require_once($CFG->libdir.'/blocklib.php');
3278             foreach ($blocks as $block) {  /// Delete any associated contexts for this block
3279
3280                 // Block instances are rarely created. Since the block instance is gone from the above delete
3281                 // statement, calling delete_context() will generate a warning as get_context_instance could
3282                 // no longer create the context as the block is already gone.
3283                 if (record_exists('context', 'contextlevel', CONTEXT_BLOCK, 'instanceid', $block->id)) {
3284                     delete_context(CONTEXT_BLOCK, $block->id);
3285                 }
3286
3287                 // fix for MDL-7164
3288                 // Get the block object and call instance_delete()
3289                 if (!$record = blocks_get_record($block->blockid)) {
3290                     $result = false;
3291                     continue;
3292                 }
3293                 if (!$obj = block_instance($record->name, $block)) {
3294                     $result = false;
3295                     continue;
3296                 }
3297                 // Return value ignored, in core mods this does not do anything, but just in case
3298                 // third party blocks might have stuff to clean up
3299                 // we execute this anyway
3300                 $obj->instance_delete();
3301             }
3302         } else {
3303             $result = false;
3304         }
3305     }
3306
3307 /// Delete any groups, removing members and grouping/course links first.
3308     require_once($CFG->dirroot.'/group/lib.php');
3309     groups_delete_groupings($courseid, true);
3310     groups_delete_groups($courseid, true);
3311
3312 /// Delete all related records in other tables that may have a courseid
3313 /// This array stores the tables that need to be cleared, as
3314 /// table_name => column_name that contains the course id.
3315
3316     $tablestoclear = array(
3317         'event' => 'courseid', // Delete events
3318         'log' => 'course', // Delete logs
3319         'course_sections' => 'course', // Delete any course stuff
3320         'course_modules' => 'course',
3321         'backup_courses' => 'courseid', // Delete scheduled backup stuff
3322         'backup_log' => 'courseid'
3323     );
3324     foreach ($tablestoclear as $table => $col) {
3325         if (delete_records($table, $col, $course->id)) {
3326             if ($showfeedback) {
3327                 notify($strdeleted . ' ' . $table);
3328             }
3329         } else {
3330             $result = false;
3331         }
3332     }
3333
3334
3335 /// Clean up metacourse stuff
3336
3337     if ($course->metacourse) {
3338         delete_records("course_meta","parent_course",$course->id);
3339         sync_metacourse($course->id); // have to do it here so the enrolments get nuked. sync_metacourses won't find it without the id.
3340         if ($showfeedback) {
3341             notify("$strdeleted course_meta");
3342         }
3343     } else {
3344         if ($parents = get_records("course_meta","child_course",$course->id)) {
3345             foreach ($parents as $parent) {
3346                 remove_from_metacourse($parent->parent_course,$parent->child_course); // this will do the unenrolments as well.
3347             }
3348             if ($showfeedback) {
3349                 notify("$strdeleted course_meta");
3350             }
3351         }
3352     }
3353
3354 /// Delete questions and question categories
3355     question_delete_course($course, $showfeedback);
3356
3357 /// Delete all roles and overiddes in the course context (but keep the course context)
3358     if ($courseid != SITEID) {
3359         delete_context(CONTEXT_COURSE, $course->id);
3360     }
3361
3362     return $result;
3363 }
3364
3365
3366 /**
3367  * This function will empty a course of USER data as much as
3368 /// possible. It will retain the activities and the structure
3369 /// of the course.
3370  *
3371  * @uses $USER
3372  * @uses $SESSION
3373  * @uses $CFG
3374  * @param object $data an object containing all the boolean settings and courseid
3375  * @param bool $showfeedback  if false then do it all silently
3376  * @return bool
3377  * @todo Finish documenting this function
3378  */
3379 function reset_course_userdata($data, $showfeedback=true) {
3380
3381     global $CFG, $USER, $SESSION;
3382     require_once($CFG->dirroot.'/group/lib.php');
3383
3384     $result = true;
3385
3386     $strdeleted = get_string('deleted');
3387
3388     // Look in every instance of every module for data to delete
3389
3390     if ($allmods = get_records('modules') ) {
3391         foreach ($allmods as $mod) {
3392             $modname = $mod->name;
3393             $modfile = $CFG->dirroot .'/mod/'. $modname .'/lib.php';
3394             $moddeleteuserdata = $modname .'_delete_userdata';   // Function to delete user data
3395             if (file_exists($modfile)) {
3396                 @include_once($modfile);
3397                 if (function_exists($moddeleteuserdata)) {
3398                     $moddeleteuserdata($data, $showfeedback);
3399                 }
3400             }
3401         }
3402     } else {
3403         error('No modules are installed!');
3404     }
3405
3406     // Delete other stuff
3407     $context = get_context_instance(CONTEXT_COURSE, $data->courseid);
3408
3409     if (!empty($data->reset_students) or !empty($data->reset_teachers)) {
3410         $teachers     = array_keys(get_users_by_capability($context, 'moodle/course:update'));
3411         $participants = array_keys(get_users_by_capability($context, 'moodle/course:view'));
3412         $students     = array_diff($participants, $teachers);
3413
3414         if (!empty($data->reset_students)) {
3415             foreach ($students as $studentid) {
3416                 role_unassign(0, $studentid, 0, $context->id);
3417             }
3418             if ($showfeedback) {
3419                 notify($strdeleted .' '.get_string('students'), 'notifysuccess');
3420             }
3421
3422             /// Delete group members (but keep the groups)
3423             $result = groups_delete_group_members($data->courseid, $showfeedback) && $result;
3424         }
3425
3426         if (!empty($data->reset_teachers)) {
3427             foreach ($teachers as $teacherid) {
3428                 role_unassign(0, $teacherid, 0, $context->id);
3429             }
3430             if ($showfeedback) {
3431                 notify($strdeleted .' '.get_string('teachers'), 'notifysuccess');
3432             }
3433         }
3434     }
3435
3436     if (!empty($data->reset_groups)) {
3437             $result = groups_delete_groupings($data->courseid, $showfeedback) && $result;
3438             $result = groups_delete_groups($data->courseid, $showfeedback) && $result;
3439     }
3440
3441     if (!empty($data->reset_events)) {
3442         if (delete_records('event', 'courseid', $data->courseid)) {
3443             if ($showfeedback) {
3444                 notify($strdeleted .' event', 'notifysuccess');
3445             }
3446         } else {
3447             $result = false;
3448         }
3449     }
3450
3451     if (!empty($data->reset_logs)) {
3452         if (delete_records('log', 'course', $data->courseid)) {
3453             if ($showfeedback) {
3454                 notify($strdeleted .' log', 'notifysuccess');
3455             }
3456         } else {
3457             $result = false;
3458         }
3459     }
3460
3461     // deletes all role assignments, and local override,
3462     // these have no courseid in table and needs separate process
3463     delete_records('role_capabilities', 'contextid', $context->id);
3464
3465     // force accessinfo refresh for users visiting this context...
3466     mark_context_dirty($context->path);
3467
3468     return $result;
3469 }
3470
3471 function generate_email_processing_address($modid,$modargs) {
3472     global $CFG;
3473
3474     if (empty($CFG->siteidentifier)) {    // Unique site identification code
3475         set_config('siteidentifier', random_string(32));
3476     }
3477
3478     $header = $CFG->mailprefix . substr(base64_encode(pack('C',$modid)),0,2).$modargs;
3479     return $header . substr(md5($header.$CFG->siteidentifier),0,16).'@'.$CFG->maildomain;
3480 }
3481
3482
3483 function moodle_process_email($modargs,$body) {
3484     // the first char should be an unencoded letter. We'll take this as an action
3485     switch ($modargs{0}) {
3486         case 'B': { // bounce
3487             list(,$userid) = unpack('V',base64_decode(substr($modargs,1,8)));
3488             if ($user = get_record_select("user","id=$userid","id,email")) {
3489                 // check the half md5 of their email
3490                 $md5check = substr(md5($user->email),0,16);
3491                 if ($md5check == substr($modargs, -16)) {
3492                     set_bounce_count($user);
3493                 }
3494                 // else maybe they've already changed it?
3495             }
3496         }
3497         break;
3498         // maybe more later?
3499     }
3500 }
3501
3502 /// CORRESPONDENCE  ////////////////////////////////////////////////
3503
3504 /**
3505  * Send an email to a specified user
3506  *
3507  * @uses $CFG
3508  * @uses $FULLME
3509  * @uses SITEID
3510  * @param user $user  A {@link $USER} object
3511  * @param user $from A {@link $USER} object
3512  * @param string $subject plain text subject line of the email
3513  * @param string $messagetext plain text version of the message
3514  * @param string $messagehtml complete html version of the message (optional)
3515  * @param string $attachment a file on the filesystem, relative to $CFG->dataroot
3516  * @param string $attachname the name of the file (extension indicates MIME)
3517  * @param bool $usetrueaddress determines whether $from email address should
3518  *          be sent out. Will be overruled by user profile setting for maildisplay
3519  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3520  *          was blocked by user and "false" if there was another sort of error.
3521  */
3522 function email_to_user($user, $from, $subject, $messagetext, $messagehtml='', $attachment='', $attachname='', $usetrueaddress=true, $replyto='', $replytoname='') {
3523
3524     global $CFG, $FULLME;
3525
3526     include_once($CFG->libdir .'/phpmailer/class.phpmailer.php');
3527
3528 /// We are going to use textlib services here
3529     $textlib = textlib_get_instance();
3530
3531     if (empty($user)) {
3532         return false;
3533     }
3534
3535     // skip mail to suspended users
3536     if (isset($user->auth) && $user->auth=='nologin') {
3537         return true;
3538     }
3539
3540     if (!empty($user->emailstop)) {
3541         return 'emailstop';
3542     }
3543
3544     if (over_bounce_threshold($user)) {
3545         error_log("User $user->id (".fullname($user).") is over bounce threshold! Not sending.");
3546         return false;
3547     }
3548
3549     $mail = new phpmailer;
3550
3551     $mail->Version = 'Moodle '. $CFG->version;           // mailer version
3552     $mail->PluginDir = $CFG->libdir .'/phpmailer/';      // plugin directory (eg smtp plugin)
3553
3554     $mail->CharSet = 'UTF-8';
3555
3556     if ($CFG->smtphosts == 'qmail') {
3557         $mail->IsQmail();                              // use Qmail system
3558
3559     } else if (empty($CFG->smtphosts)) {
3560         $mail->IsMail();                               // use PHP mail() = sendmail
3561
3562     } else {
3563         $mail->IsSMTP();                               // use SMTP directly
3564         if (!empty($CFG->debugsmtp)) {
3565             echo '<pre>' . "\n";
3566             $mail->SMTPDebug = true;
3567         }
3568         $mail->Host = $CFG->smtphosts;               // specify main and backup servers
3569
3570         if ($CFG->smtpuser) {                          // Use SMTP authentication
3571             $mail->SMTPAuth = true;
3572             $mail->Username = $CFG->smtpuser;
3573             $mail->Password = $CFG->smtppass;
3574         }
3575     }
3576
3577     $supportuser = generate_email_supportuser();
3578
3579
3580     // make up an email address for handling bounces
3581     if (!empty($CFG->handlebounces)) {
3582         $modargs = 'B'.base64_encode(pack('V',$user->id)).substr(md5($user->email),0,16);
3583         $mail->Sender = generate_email_processing_address(0,$modargs);
3584     } else {
3585         $mail->Sender   = $supportuser->email;
3586     }
3587
3588     if (is_string($from)) { // So we can pass whatever we want if there is need
3589         $mail->From     = $CFG->noreplyaddress;
3590         $mail->FromName = $from;
3591     } else if ($usetrueaddress and $from->maildisplay) {
3592         $mail->From     = $from->email;
3593         $mail->FromName = fullname($from);
3594     } else {
3595         $mail->From     = $CFG->noreplyaddress;
3596         $mail->FromName = fullname($from);
3597         if (empty($replyto)) {
3598             $mail->AddReplyTo($CFG->noreplyaddress,get_string('noreplyname'));
3599         }
3600     }
3601
3602     if (!empty($replyto)) {
3603         $mail->AddReplyTo($replyto,$replytoname);
3604     }
3605
3606     $mail->Subject = substr(stripslashes($subject), 0, 900);
3607
3608     $mail->AddAddress($user->email, fullname($user) );
3609
3610     $mail->WordWrap = 79;                               // set word wrap
3611
3612     if (!empty($from->customheaders)) {                 // Add custom headers
3613         if (is_array($from->customheaders)) {
3614             foreach ($from->customheaders as $customheader) {
3615                 $mail->AddCustomHeader($customheader);
3616             }
3617         } else {
3618             $mail->AddCustomHeader($from->customheaders);
3619         }
3620     }
3621
3622     if (!empty($from->priority)) {
3623         $mail->Priority = $from->priority;
3624     }
3625
3626     if ($messagehtml && $user->mailformat == 1) { // Don't ever send HTML to users who don't want it
3627         $mail->IsHTML(true);
3628         $mail->Encoding = 'quoted-printable';           // Encoding to use
3629         $mail->Body    =  $messagehtml;
3630         $mail->AltBody =  "\n$messagetext\n";
3631     } else {
3632         $mail->IsHTML(false);
3633         $mail->Body =  "\n$messagetext\n";
3634     }
3635
3636     if ($attachment && $attachname) {
3637         if (ereg( "\\.\\." ,$attachment )) {    // Security check for ".." in dir path
3638             $mail->AddAddress($supportuser->email, fullname($supportuser, true) );
3639             $mail->AddStringAttachment('Error in attachment.  User attempted to attach a filename with a unsafe name.', 'error.txt', '8bit', 'text/plain');
3640         } else {
3641             require_once($CFG->libdir.'/filelib.php');
3642             $mimetype = mimeinfo('type', $attachname);
3643             $mail->AddAttachment($CFG->dataroot .'/'. $attachment, $attachname, 'base64', $mimetype);
3644         }
3645     }
3646
3647
3648
3649 /// If we are running under Unicode and sitemailcharset or allowusermailcharset are set, convert the email
3650 /// encoding to the specified one
3651     if ((!empty($CFG->sitemailcharset) || !empty($CFG->allowusermailcharset))) {
3652     /// Set it to site mail charset
3653         $charset = $CFG->sitemailcharset;
3654     /// Overwrite it with the user mail charset
3655         if (!empty($CFG->allowusermailcharset)) {
3656             if ($useremailcharset = get_user_preferences('mailcharset', '0', $user->id)) {
3657                 $charset = $useremailcharset;
3658             }
3659         }
3660     /// If it has changed, convert all the necessary strings
3661         $charsets = get_list_of_charsets();
3662         unset($charsets['UTF-8']);
3663         if (in_array($charset, $charsets)) {
3664         /// Save the new mail charset
3665             $mail->CharSet = $charset;
3666         /// And convert some strings
3667             $mail->FromName = $textlib->convert($mail->FromName, 'utf-8', $mail->CharSet); //From Name
3668             foreach ($mail->ReplyTo as $key => $rt) {                                      //ReplyTo Names
3669                 $mail->ReplyTo[$key][1] = $textlib->convert($rt, 'utf-8', $mail->CharSet);
3670             }
3671             $mail->Subject = $textlib->convert($mail->Subject, 'utf-8', $mail->CharSet);   //Subject
3672             foreach ($mail->to as $key => $to) {
3673                 $mail->to[$key][1] = $textlib->convert($to, 'utf-8', $mail->CharSet);      //To Names
3674             }
3675             $mail->Body = $textlib->convert($mail->Body, 'utf-8', $mail->CharSet);         //Body
3676             $mail->AltBody = $textlib->convert($mail->AltBody, 'utf-8', $mail->CharSet);   //Subject
3677         }
3678     }
3679
3680     if ($mail->Send()) {
3681         set_send_count($user);
3682         $mail->IsSMTP();                               // use SMTP directly
3683         if (!empty($CFG->debugsmtp)) {
3684             echo '</pre>';
3685         }
3686         return true;
3687     } else {
3688         mtrace('ERROR: '. $mail->ErrorInfo);
3689         add_to_log(SITEID, 'library', 'mailer', $FULLME, 'ERROR: '. $mail->ErrorInfo);
3690         if (!empty($CFG->debugsmtp)) {
3691             echo '</pre>';
3692         }
3693         return false;
3694     }
3695 }
3696
3697 /**
3698  * Generate a signoff for emails based on support settings
3699  *
3700  */
3701 function generate_email_signoff() {
3702     global $CFG;
3703
3704     $signoff = "\n";
3705     if (!empty($CFG->supportname)) {
3706         $signoff .= $CFG->supportname."\n";
3707     }
3708     if (!empty($CFG->supportemail)) {
3709         $signoff .= $CFG->supportemail."\n";
3710     }
3711     if (!empty($CFG->supportpage)) {
3712         $signoff .= $CFG->supportpage."\n";
3713     }
3714     return $signoff;
3715 }
3716
3717 /**
3718  * Generate a fake user for emails based on support settings
3719  *
3720  */
3721 function generate_email_supportuser() {
3722
3723     global $CFG;
3724
3725     static $supportuser;
3726
3727     if (!empty($supportuser)) {
3728         return $supportuser;
3729     }
3730
3731     $supportuser = new object;
3732     $supportuser->email = $CFG->supportemail ? $CFG->supportemail : $CFG->noreplyaddress;
3733     $supportuser->firstname = $CFG->supportname ? $CFG->supportname : get_string('noreplyname');
3734     $supportuser->lastname = '';
3735     $supportuser->maildisplay = true;
3736
3737     return $supportuser;
3738 }
3739
3740
3741 /**
3742  * Sets specified user's password and send the new password to the user via email.
3743  *
3744  * @uses $CFG
3745  * @param user $user A {@link $USER} object
3746  * @return boolean|string Returns "true" if mail was sent OK, "emailstop" if email
3747  *          was blocked by user and "false" if there was another sort of error.
3748  */
3749 function setnew_password_and_mail($user) {
3750
3751     global $CFG;
3752
3753     $site  = get_site();
3754
3755     $supportuser = generate_email_supportuser();
3756
3757     $newpassword = generate_password();
3758
3759     if (! set_field('user', 'password', md5($newpassword), 'id', $user->id) ) {
3760         trigger_error('Could not set user password!');
3761         return false;
3762     }
3763
3764     $a = new object();
3765     $a->firstname   = fullname($user, true);
3766     $a->sitename    = format_string($site->fullname);
3767     $a->username    = $user->username;
3768     $a->newpassword = $newpassword;
3769     $a->link        = $CFG->wwwroot .'/login/';
3770     $a->signoff     = generate_email_signoff();
3771
3772     $message = get_string('newusernewpasswordtext', '', $a);
3773
3774     $subject  = format_string($site->fullname) .': '. get_string('newusernewpasswordsubj');
3775
3776     return email_to_user($user, $supportuser, $subject, $message);
3777
3778 }
3779
3780 /**
3781  * Resets specified user's password and send the new password to the user via email.
3782  *
3783  * @uses $CFG
3784  * @param user $user A {@link $USER} object
3785  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3786  *          was blocked by user and "false" if there was another sort of error.
3787  */
3788 function reset_password_and_mail($user) {
3789
3790     global $CFG;
3791
3792     $site  = get_site();
3793     $supportuser = generate_email_supportuser();
3794
3795     $userauth = get_auth_plugin($user->auth);
3796     if (!$userauth->can_reset_password() or !is_enabled_auth($user->auth)) {
3797         trigger_error("Attempt to reset user password for user $user->username with Auth $user->auth.");
3798         return false;
3799     }
3800
3801     $newpassword = generate_password();
3802
3803     if (!$userauth->user_update_password(addslashes_recursive($user), addslashes($newpassword))) {
3804         error("Could not set user password!");
3805     }
3806
3807     $a = new object();
3808     $a->firstname = $user->firstname;
3809     $a->sitename = format_string($site->fullname);
3810     $a->username = $user->username;
3811     $a->newpassword = $newpassword;
3812     $a->link = $CFG->httpswwwroot .'/login/change_password.php';
3813     $a->signoff = generate_email_signoff();
3814
3815     $message = get_string('newpasswordtext', '', $a);
3816
3817     $subject  = format_string($site->fullname) .': '. get_string('changedpassword');
3818
3819     return email_to_user($user, $supportuser, $subject, $message);
3820
3821 }
3822
3823 /**
3824  * Send email to specified user with confirmation text and activation link.
3825  *
3826  * @uses $CFG
3827  * @param user $user A {@link $USER} object
3828  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3829  *          was blocked by user and "false" if there was another sort of error.
3830  */
3831  function send_confirmation_email($user) {
3832
3833     global $CFG;
3834
3835     $site = get_site();
3836     $supportuser = generate_email_supportuser();
3837
3838     $data = new object();
3839     $data->firstname = fullname($user);
3840     $data->sitename = format_string($site->fullname);
3841     $data->admin = generate_email_signoff();
3842
3843     $subject = get_string('emailconfirmationsubject', '', format_string($site->fullname));
3844
3845     $data->link = $CFG->wwwroot .'/login/confirm.php?data='. $user->secret .'/'. urlencode($user->username);
3846     $message     = get_string('emailconfirmation', '', $data);
3847     $messagehtml = text_to_html(get_string('emailconfirmation', '', $data), false, false, true);
3848
3849     $user->mailformat = 1;  // Always send HTML version as well
3850
3851     return email_to_user($user, $supportuser, $subject, $message, $messagehtml);
3852
3853 }
3854
3855 /**
3856  * send_password_change_confirmation_email.
3857  *
3858  * @uses $CFG
3859  * @param user $user A {@link $USER} object
3860  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3861  *          was blocked by user and "false" if there was another sort of error.
3862  */
3863 function send_password_change_confirmation_email($user) {
3864
3865     global $CFG;
3866
3867     $site = get_site();
3868     $supportuser = generate_email_supportuser();
3869
3870     $data = new object();
3871     $data->firstname = $user->firstname;
3872     $data->sitename = format_string($site->fullname);
3873     $data->link = $CFG->httpswwwroot .'/login/forgot_password.php?p='. $user->secret .'&s='. urlencode($user->username);
3874     $data->admin = generate_email_signoff();
3875
3876     $message = get_string('emailpasswordconfirmation', '', $data);
3877     $subject = get_string('emailpasswordconfirmationsubject', '', format_string($site->fullname));
3878
3879     return email_to_user($user, $supportuser, $subject, $message);
3880
3881 }
3882
3883 /**
3884  * send_password_change_info.
3885  *
3886  * @uses $CFG
3887  * @param user $user A {@link $USER} object
3888  * @return bool|string Returns "true" if mail was sent OK, "emailstop" if email
3889  *          was blocked by user and "false" if there was another sort of error.
3890  */
3891 function send_password_change_info($user) {
3892
3893     global $CFG;
3894
3895     $site = get_site();
3896     $supportuser = generate_email_supportuser();
3897     $systemcontext = get_context_instance(CONTEXT_SYSTEM);
3898
3899     $data = new object();
3900     $data->firstname = $user->firstname;
3901     $data->sitename = format_string($site->fullname);
3902     $data->admin = generate_email_signoff();
3903
3904     $userauth = get_auth_plugin($user->auth);
3905
3906     if (!is_enabled_auth($user->auth) or $user->auth == 'nologin') {
3907         $message = get_string('emailpasswordchangeinfodisabled', '', $data);
3908         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3909         return email_to_user($user, $supportuser, $subject, $message);
3910     }
3911
3912     if ($userauth->can_change_password() and $userauth->change_password_url()) {
3913         // we have some external url for password changing
3914         $data->link .= $userauth->change_password_url();
3915
3916     } else {
3917         //no way to change password, sorry
3918         $data->link = '';
3919     }
3920
3921     if (!empty($data->link) and has_capability('moodle/user:changeownpassword', $systemcontext, $user->id)) {
3922         $message = get_string('emailpasswordchangeinfo', '', $data);
3923         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3924     } else {
3925         $message = get_string('emailpasswordchangeinfofail', '', $data);
3926         $subject = get_string('emailpasswordchangeinfosubject', '', format_string($site->fullname));
3927     }
3928
3929     return email_to_user($user, $supportuser, $subject, $message);
3930
3931 }
3932
3933 /**
3934  * Check that an email is allowed.  It returns an error message if there
3935  * was a problem.
3936  *
3937  * @uses $CFG
3938  * @param  string $email Content of email
3939  * @return string|false
3940  */
3941 function email_is_not_allowed($email) {
3942
3943     global $CFG;
3944
3945     if (!empty($CFG->allowemailaddresses)) {
3946         $allowed = explode(' ', $CFG->allowemailaddresses);
3947         foreach ($allowed as $allowedpattern) {
3948             $allowedpattern = trim($allowedpattern);
3949             if (!$allowedpattern) {
3950                 continue;
3951             }
3952             if (strpos(strrev($email), strrev('@'.$allowedpattern)) === 0) { // Match!   (bug 5250)
3953                 return false;
3954             }
3955         }
3956         return get_string('emailonlyallowed', '', $CFG->allowemailaddresses);
3957
3958     } else if (!empty($CFG->denyemailaddresses)) {
3959         $denied = explode(' ', $CFG->denyemailaddresses);
3960         foreach ($denied as $deniedpattern) {
3961             $deniedpattern = trim($deniedpattern);
3962             if (!$deniedpattern) {
3963                 continue;
3964             }
3965             if (strpos(strrev($email), strrev('@'.$deniedpattern)) === 0) { // Match!   (bug 5250)
3966                 return get_string('emailnotallowed', '', $CFG->denyemailaddresses);
3967             }
3968         }
3969     }
3970
3971     return false;
3972 }
3973
3974 function email_welcome_message_to_user($course, $user=NULL) {
3975     global $CFG, $USER;
3976
3977     if (empty($user)) {
3978         if (!isloggedin()) {
3979             return false;
3980         }
3981         $user = $USER;
3982     }
3983
3984     if (!empty($course->welcomemessage)) {
3985         $subject = get_string('welcometocourse', '', format_string($course->fullname));
3986
3987         $a->coursename = $course->fullname;
3988         $a->profileurl = "$CFG->wwwroot/user/view.php?id=$USER->id&course=$course->id";
3989         //$message = get_string("welcometocoursetext", "", $a);
3990         $message = $course->welcomemessage;
3991
3992         if (! $teacher = get_teacher($course->id)) {
3993             $teacher = get_admin();
3994         }
3995         email_to_user($user, $teacher, $subject, $message);
3996     }
3997 }
3998
3999 /// FILE HANDLING  /////////////////////////////////////////////
4000
4001
4002 /**
4003  * Makes an upload directory for a particular module.
4004  *
4005  * @uses $CFG
4006  * @param int $courseid The id of the course in question - maps to id field of 'course' table.
4007  * @return string|false Returns full path to directory if successful, false if not
4008  */
4009 function make_mod_upload_directory($courseid) {
4010     global $CFG;
4011
4012     if (! $moddata = make_upload_directory($courseid .'/'. $CFG->moddata)) {
4013         return false;
4014     }
4015
4016     $strreadme = get_string('readme');
4017
4018     if (file_exists($CFG->dirroot .'/lang/'. $CFG->lang .'/docs/module_files.txt')) {
4019         copy($CFG->dirroot .'/lang/'. $CFG->lang .'/docs/module_files.txt', $moddata .'/'. $strreadme .'.txt');
4020     } else {
4021         copy($CFG->dirroot .'/lang/en_utf8/docs/module_files.txt', $moddata .'/'. $strreadme .'.txt');
4022     }
4023     return $moddata;
4024 }
4025
4026 /**
4027  * Returns current name of file on disk if it exists.
4028  *
4029  * @param string $newfile File to be verified
4030  * @return string Current name of file on disk if true
4031  */
4032 function valid_uploaded_file($newfile) {
4033     if (empty($newfile)) {
4034         return '';
4035     }
4036     if (is_uploaded_file($newfile['tmp_name']) and $newfile['size'] > 0) {
4037         return $newfile['tmp_name'];
4038     } else {
4039         return '';
4040     }
4041 }
4042
4043 /**
4044  * Returns the maximum size for uploading files.
4045  *
4046  * There are seven possible upload limits:
4047  * 1. in Apache using LimitRequestBody (no way of checking or changing this)
4048  * 2. in php.ini for 'upload_max_filesize' (can not be changed inside PHP)
4049  * 3. in .htaccess for 'upload_max_filesize' (can not be changed inside PHP)
4050  * 4. in php.ini for 'post_max_size' (can not be changed inside PHP)
4051  * 5. by the Moodle admin in $CFG->maxbytes
4052  * 6. by the teacher in the current course $course->maxbytes
4053  * 7. by the teacher for the current module, eg $assignment->maxbytes
4054  *
4055  * These last two are passed to this function as arguments (in bytes).
4056  * Anything defined as 0 is ignored.
4057  * The smallest of all the non-zero numbers is returned.
4058  *
4059  * @param int $sizebytes ?
4060  * @param int $coursebytes Current course $course->maxbytes (in bytes)
4061  * @param int $modulebytes Current module ->maxbytes (in bytes)
4062  * @return int The maximum size for uploading files.
4063  * @todo Finish documenting this function
4064  */
4065 function get_max_upload_file_size($sitebytes=0, $coursebytes=0, $modulebytes=0) {
4066
4067     if (! $filesize = ini_get('upload_max_filesize')) {
4068         $filesize = '5M';
4069     }
4070     $minimumsize = get_real_size($filesize);
4071
4072     if ($postsize = ini_get('post_max_size')) {
4073         $postsize = get_real_size($postsize);
4074         if ($postsize < $minimumsize) {
4075             $minimumsize = $postsize;
4076         }
4077     }
4078
4079     if ($sitebytes and $sitebytes < $minimumsize) {
4080         $minimumsize = $sitebytes;
4081     }
4082
4083     if ($coursebytes and $coursebytes < $minimumsize) {
4084         $minimumsize = $coursebytes;
4085     }
4086
4087     if ($modulebytes and $modulebytes < $minimumsize) {
4088         $minimumsize = $modulebytes;
4089     }
4090
4091     return $minimumsize;
4092 }
4093
4094 /**
4095  * Related to {@link get_max_upload_file_size()} - this function returns an
4096  * array of possible sizes in an array, translated to the
4097  * local language.
4098  *
4099  * @uses SORT_NUMERIC
4100  * @param int $sizebytes ?
4101  * @param int $coursebytes Current course $course->maxbytes (in bytes)
4102  * @param int $modulebytes Current module ->maxbytes (in bytes)
4103  * @return int
4104  * @todo Finish documenting this function
4105  */
4106 function get_max_upload_sizes($sitebytes=0, $coursebytes=0, $modulebytes=0) {
4107     global $CFG;
4108
4109     if (!$maxsize = get_max_upload_file_size($sitebytes, $coursebytes, $modulebytes)) {
4110         return array();
4111     }
4112
4113     $filesize[$maxsize] = display_size($maxsize);
4114
4115     $sizelist = array(10240, 51200, 102400, 512000, 1048576, 2097152,
4116                       5242880, 10485760, 20971520, 52428800, 104857600);
4117
4118     // Allow maxbytes to be selected if it falls outside the above boundaries
4119     if( isset($CFG->maxbytes) && !in_array($CFG->maxbytes, $sizelist) ){
4120             $sizelist[] = $CFG->maxbytes;
4121     }
4122
4123     foreach ($sizelist as $sizebytes) {
4124        if ($sizebytes < $maxsize) {
4125            $filesize[$sizebytes] = display_size($sizebytes);
4126        }
4127     }
4128
4129     krsort($filesize, SORT_NUMERIC);
4130
4131     return $filesize;
4132 }
4133
4134 /**
4135  * If there has been an error uploading a file, print the appropriate error message
4136  * Numerical constants used as constant definitions not added until PHP version 4.2.0
4137  *
4138  * $filearray is a 1-dimensional sub-array of the $_FILES array
4139  * eg $filearray = $_FILES['userfile1']
4140  * If left empty then the first element of the $_FILES array will be used
4141  *
4142  * @uses $_FILES
4143  * @param array $filearray  A 1-dimensional sub-array of the $_FILES array
4144  * @param bool $returnerror If true then a string error message will be returned. Otherwise the user will be notified of the error in a notify() call.
4145  * @return bool|string
4146  */
4147 function print_file_upload_error($filearray = '', $returnerror = false) {
4148
4149     if ($filearray == '' or !isset($filearray['error'])) {
4150
4151         if (empty($_FILES)) return false;
4152
4153         $files = $_FILES; /// so we don't mess up the _FILES array for subsequent code
4154         $filearray = array_shift($files); /// use first element of array
4155     }
4156
4157     switch ($filearray['error']) {
4158
4159         case 0: // UPLOAD_ERR_OK
4160             if ($filearray['size'] > 0) {
4161                 $errmessage = get_string('uploadproblem', $filearray['name']);
4162             } else {
4163                 $errmessage = get_string('uploadnofilefound'); /// probably a dud file name
4164             }
4165             break;
4166
4167         case 1: // UPLOAD_ERR_INI_SIZE
4168             $errmessage = get_string('uploadserverlimit');
4169             break;
4170
4171         case 2: // UPLOAD_ERR_FORM_SIZE
4172             $errmessage = get_string('uploadformlimit');
4173             break;
4174
4175         case 3: // UPLOAD_ERR_PARTIAL
4176             $errmessage = get_string('uploadpartialfile');
4177             break;
4178
4179         case 4: // UPLOAD_ERR_NO_FILE
4180             $errmessage = get_string('uploadnofilefound');
4181             break;
4182
4183         default:
4184             $errmessage = get_string('uploadproblem', $filearray['name']);
4185     }
4186
4187     if ($returnerror) {
4188         return $errmessage;
4189     } else {
4190         notify($errmessage);
4191         return true;
4192     }
4193
4194 }
4195
4196 /**
4197  * handy function to loop through an array of files and resolve any filename conflicts
4198  * both in the array of filenames and for what is already on disk.
4199  * not really compatible with the similar function in uploadlib.php
4200  * but this could be used for files/index.php for moving files around.
4201  */
4202
4203 function resolve_filename_collisions($destination,$files,$format='%s_%d.%s') {
4204     foreach ($files as $k => $f) {
4205         if (check_potential_filename($destination,$f,$files)) {
4206             $bits = explode('.', $f);
4207             for ($i = 1; true; $i++) {
4208                 $try = sprintf($format, $bits[0], $i, $bits[1]);
4209                 if (!check_potential_filename($destination,$try,$files)) {
4210                     $files[$k] = $try;
4211                     break;
4212                 }
4213             }
4214         }
4215     }
4216     return $files;
4217 }
4218
4219 /**
4220  * @used by resolve_filename_collisions
4221  */
4222 function check_potential_filename($destination,$filename,$files) {
4223     if (file_exists($destination.'/'.$filename)) {
4224         return true;
4225     }
4226     if (count(array_keys($files,$filename)) > 1) {
4227         return true;
4228     }
4229     return false;
4230 }
4231
4232
4233 /**
4234  * Returns an array with all the filenames in
4235  * all subdirectories, relative to the given rootdir.
4236  * If excludefile is defined, then that file/directory is ignored
4237  * If getdirs is true, then (sub)directories are included in the output
4238  * If getfiles is true, then files are included in the output
4239  * (at least one of these must be true!)
4240  *
4241  * @param string $rootdir  ?
4242  * @param string $excludefile  If defined then the specified file/directory is ignored
4243  * @param bool $descend  ?
4244  * @param bool $getdirs  If true then (sub)directories are included in the output
4245  * @param bool $getfiles  If true then files are included in the output
4246  * @return array An array with all the filenames in
4247  * all subdirectories, relative to the given rootdir
4248  * @todo Finish documenting this function. Add examples of $excludefile usage.
4249  */
4250 function get_directory_list($rootdir, $excludefiles='', $descend=true, $getdirs=false, $getfiles=true) {
4251
4252     $dirs = array();
4253
4254     if (!$getdirs and !$getfiles) {   // Nothing to show
4255         return $dirs;
4256     }
4257
4258     if (!is_dir($rootdir)) {          // Must be a directory
4259         return $dirs;
4260     }
4261
4262     if (!$dir = opendir($rootdir)) {  // Can't open it for some reason
4263         return $dirs;
4264     }
4265
4266     if (!is_array($excludefiles)) {
4267         $excludefiles = array($excludefiles);
4268     }
4269
4270     while (false !== ($file = readdir($dir))) {
4271         $firstchar = substr($file, 0, 1);
4272         if ($firstchar == '.' or $file == 'CVS' or in_array($file, $excludefiles)) {
4273             continue;
4274         }
4275         $fullfile = $rootdir .'/'. $file;
4276         if (filetype($fullfile) == 'dir') {
4277             if ($getdirs) {
4278                 $dirs[] = $file;
4279             }
4280             if ($descend) {
4281                 $subdirs = get_directory_list($fullfile, $excludefiles, $descend, $getdirs, $getfiles);
4282                 foreach ($subdirs as $subdir) {
4283                     $dirs[] = $file .'/'. $subdir;
4284                 }
4285             }
4286         } else if ($getfiles) {
4287             $dirs[] = $file;
4288         }
4289     }
4290     closedir($dir);
4291
4292     asort($dirs);
4293
4294     return $dirs;
4295 }
4296
4297
4298 /**
4299  * Adds up all the files in a directory and works out the size.
4300  *
4301  * @param string $rootdir  ?
4302  * @param string $excludefile  ?
4303  * @return array
4304  * @todo Finish documenting this function
4305  */
4306 function get_directory_size($rootdir, $excludefile='') {
4307
4308     global $CFG;
4309
4310     // do it this way if we can, it's much faster
4311     if (!empty($CFG->pathtodu) && is_executable(trim($CFG->pathtodu))) {
4312         $command = trim($CFG->pathtodu).' -sk --apparent-size '.escapeshellarg($rootdir);
4313         $output = null;
4314         $return = null;
4315         exec($command,$output,$return);
4316         if (is_array($output)) {
4317             return get_real_size(intval($output[0]).'k'); // we told it to return k.
4318         }
4319     }
4320
4321     if (!is_dir($rootdir)) {          // Must be a directory
4322         return 0;
4323     }
4324
4325     if (!$dir = @opendir($rootdir)) {  // Can't open it for some reason
4326         return 0;
4327     }
4328
4329     $size = 0;
4330
4331     while (false !== ($file = readdir($dir))) {
4332         $firstchar = substr($file, 0, 1);
4333         if ($firstchar == '.' or $file == 'CVS' or $file == $excludefile) {
4334             continue;
4335         }
4336         $fullfile = $rootdir .'/'. $file;
4337         if (filetype($fullfile) == 'dir') {
4338             $size += get_directory_size($fullfile, $excludefile);
4339         } else {
4340             $size += filesize($fullfile);
4341         }
4342     }
4343     closedir($dir);
4344
4345     return $size;
4346 }
4347
4348 /**
4349  * Converts bytes into display form
4350  *
4351  * @param string $size  ?
4352  * @return string
4353  * @staticvar string $gb Localized string for size in gigabytes
4354  * @staticvar string $mb Localized string for size in megabytes
4355  * @staticvar string $kb Localized string for size in kilobytes
4356  * @staticvar string $b Localized string for size in bytes
4357  * @todo Finish documenting this function. Verify return type.
4358  */
4359 function display_size($size) {
4360
4361     static $gb, $mb, $kb, $b;
4362
4363     if (empty($gb)) {
4364         $gb = get_string('sizegb');
4365         $mb = get_string('sizemb');
4366         $kb = get_string('sizekb');
4367         $b  = get_string('sizeb');
4368     }
4369
4370     if ($size >= 1073741824) {
4371         $size = round($size / 1073741824 * 10) / 10 . $gb;
4372     } else if ($size >= 1048576) {
4373         $size = round($size / 1048576 * 10) / 10 . $mb;
4374     } else if ($size >= 1024) {
4375         $size = round($size / 1024 * 10) / 10 . $kb;
4376     } else {
4377         $size = $size .' '. $b;
4378     }
4379     return $size;
4380 }
4381
4382 /**
4383  * Cleans a given filename by removing suspicious or troublesome characters
4384  * Only these are allowed: alphanumeric _ - .
4385  * Unicode characters can be enabled by setting $CFG->unicodecleanfilename = true in config.php
4386  *
4387  * WARNING: unicode characters may not be compatible with zip compression in backup/restore,
4388  *          because native zip binaries do weird character conversions. Use PHP zipping instead.
4389  *
4390  * @param string $string  file name
4391  * @return string cleaned file name
4392  */
4393 function clean_filename($string) {
4394     global $CFG;
4395     if (empty($CFG->unicodecleanfilename)) {
4396         $textlib = textlib_get_instance();
4397         $string = $textlib->specialtoascii($string);
4398         $string = preg_replace('/[^\.a-zA-Z\d\_-]/','_', $string ); // only allowed chars
4399     } else {
4400         //clean only ascii range
4401         $string = preg_replace("/[\\000-\\x2c\\x2f\\x3a-\\x40\\x5b-\\x5e\\x60\\x7b-\\177]/s", '_', $string);
4402     }
4403     $string = preg_replace("/_+/", '_', $string);
4404     $string = preg_replace("/\.\.+/", '.', $string);
4405     return $string;
4406 }
4407
4408
4409 /// STRING TRANSLATION  ////////////////////////////////////////
4410
4411 /**
4412  * Returns the code for the current language
4413  *
4414  * @uses $CFG
4415  * @param $USER
4416  * @param $SESSION
4417  * @return string
4418  */
4419 function current_language() {
4420     global $CFG, $USER, $SESSION, $COURSE;
4421
4422     if (!empty($COURSE->id) and $COURSE->id != SITEID and !empty($COURSE->lang)) {    // Course language can override all other settings for this page
4423         $return = $COURSE->lang;
4424
4425     } else if (!empty($SESSION->lang)) {    // Session language can override other settings
4426         $return = $SESSION->lang;
4427
4428     } else if (!empty($USER->lang)) {
4429         $return = $USER->lang;
4430
4431     } else {
4432         $return = $CFG->lang;
4433     }
4434
4435     if ($return == 'en') {
4436         $return = 'en_utf8';
4437     }
4438
4439     return $return;
4440 }
4441
4442 /**
4443  * Prints out a translated string.
4444  *
4445  * Prints out a translated string using the return value from the {@link get_string()} function.
4446  *
4447  * Example usage of this function when the string is in the moodle.php file:<br/>
4448  * <code>
4449  * echo '<strong>';
4450  * print_string('wordforstudent');
4451  * echo '</strong>';
4452  * </code>
4453  *
4454  * Example usage of this function when the string is not in the moodle.php file:<br/>
4455  * <code>
4456  * echo '<h1>';
4457  * print_string('typecourse', 'calendar');
4458  * echo '</h1>';
4459  * </code>
4460  *
4461  * @param string $identifier The key identifier for the localized string
4462  * @param string $module The module where the key identifier is stored. If none is specified then moodle.php is used.
4463  * @param mixed $a An object, string or number that can be used
4464  * within translation strings
4465  */
4466 function print_string($identifier, $module='', $a=NULL) {
4467     echo get_string($identifier, $module, $a);
4468 }
4469
4470 /**
4471  * fix up the optional data in get_string()/print_string() etc
4472  * ensure possible sprintf() format characters are escaped correctly
4473  * needs to handle arbitrary strings and objects
4474  * @param mixed $a An object, string or number that can be used
4475  * @return mixed the supplied parameter 'cleaned'
4476  */
4477 function clean_getstring_data( $a ) {
4478     if (is_string($a)) {
4479         return str_replace( '%','%%',$a );
4480     }
4481     elseif (is_object($a)) {
4482         $a_vars = get_object_vars( $a );
4483         $new_a_vars = array();
4484         foreach ($a_vars as $fname => $a_var) {
4485             $new_a_vars[$fname] = clean_getstring_data( $a_var );
4486         }
4487         return (object)$new_a_vars;
4488     }
4489     else {
4490         return $a;
4491     }
4492 }
4493
4494 /**
4495  * @return array places to look for lang strings based on the prefix to the
4496  * module name. For example qtype_ in question/type. Used by get_string and
4497  * help.php.
4498  */
4499 function places_to_search_for_lang_strings() {
4500     global $CFG;
4501
4502     return array(
4503         '__exceptions' => array('moodle', 'langconfig'),
4504         'assignment_' => array('mod/assignment/type'),
4505         'auth_' => array('auth'),
4506         'block_' => array('blocks'),
4507         'datafield_' => array('mod/data/field'),
4508         'datapreset_' => array('mod/data/preset'),
4509         'enrol_' => array('enrol'),
4510         'format_' => array('course/format'),
4511         'qtype_' => array('question/type'),
4512         'report_' => array($CFG->admin.'/report', 'course/report', 'mod/quiz/report'),
4513         'resource_' => array('mod/resource/type'),
4514         'gradereport_' => array('grade/report'),
4515         'gradeimport_' => array('grade/import'),
4516         'gradeexport_' => array('grade/export'),
4517         '' => array('mod')
4518     );
4519 }
4520
4521 /**
4522  * Returns a localized string.
4523  *
4524  * Returns the translated string specified by $identifier as
4525  * for $module.  Uses the same format files as STphp.
4526  * $a is an object, string or number that can be used
4527  * within translation strings
4528  *
4529  * eg "hello \$a->firstname \$a->lastname"
4530  * or "hello \$a"
4531  *
4532  * If you would like to directly echo the localized string use
4533  * the function {@link print_string()}
4534  *
4535  * Example usage of this function involves finding the string you would
4536  * like a local equivalent of and using its identifier and module information
4537  * to retrive it.<br/>
4538  * If you open moodle/lang/en/moodle.php and look near line 1031
4539  * you will find a string to prompt a user for their word for student
4540  * <code>
4541  * $string['wordforstudent'] = 'Your word for Student';
4542  * </code>
4543  * So if you want to display the string 'Your word for student'
4544  * in any language that supports it on your site
4545  * you just need to use the identifier 'wordforstudent'
4546  * <code>
4547  * $mystring = '<strong>'. get_string('wordforstudent') .'</strong>';
4548 or
4549  * </code>
4550  * If the string you want is in another file you'd take a slightly
4551  * different approach. Looking in moodle/lang/en/calendar.php you find
4552  * around line 75:
4553  * <code>
4554  * $string['typecourse'] = 'Course event';
4555  * </code>
4556  * If you want to display the string "Course event" in any language
4557  * supported you would use the identifier 'typecourse' and the module 'calendar'
4558  * (because it is in the file calendar.php):
4559  * <code>
4560  * $mystring = '<h1>'. get_string('typecourse', 'calendar') .'</h1>';
4561  * </code>
4562  *
4563  * As a last resort, should the identifier fail to map to a string
4564  * the returned string will be [[ $identifier ]]
4565  *
4566  * @uses $CFG
4567  * @param string $identifier The key identifier for the localized string
4568  * @param string $module The module where the key identifier is stored. If none is specified then moodle.php is used.
4569  * @param mixed $a An object, string or number that can be used
4570  * within translation strings
4571  * @param array $extralocations An array of strings with other locations to look for string files
4572  * @return string The localized string.
4573  */
4574 function get_string($identifier, $module='', $a=NULL, $extralocations=NULL) {
4575
4576     global $CFG;
4577
4578 /// originally these special strings were stored in moodle.php now we are only in langconfig.php
4579     $langconfigstrs = array('alphabet', 'backupnameformat', 'decsep', 'firstdayofweek', 'listsep', 'locale',
4580                             'localewin', 'localewincharset', 'oldcharset',
4581                             'parentlanguage', 'strftimedate', 'strftimedateshort', 'strftimedatetime',
4582                             'strftimedaydate', 'strftimedaydatetime', 'strftimedayshort', 'strftimedaytime',
4583                             'strftimemonthyear', 'strftimerecent', 'strftimerecentfull', 'strftimetime',
4584                             'thischarset', 'thisdirection', 'thislanguage');
4585
4586     $filetocheck = 'langconfig.php';
4587     $defaultlang = 'en_utf8';
4588     if (in_array($identifier, $langconfigstrs)) {
4589         $module = 'langconfig';  //This strings are under langconfig.php for 1.6 lang packs
4590     }
4591
4592     $lang = current_language();
4593
4594     if ($module == '') {
4595         $module = 'moodle';
4596     }
4597
4598     // if $a happens to have % in it, double it so sprintf() doesn't break
4599     if ($a) {
4600         $a = clean_getstring_data( $a );
4601     }
4602
4603 /// Define the two or three major locations of language strings for this module
4604     $locations = array();
4605
4606     if (!empty($extralocations)) {   // Calling code has a good idea where to look
4607         if (is_array($extralocations)) {
4608             $locations += $extralocations;
4609         } else if (is_string($extralocations)) {
4610             $locations[] = $extralocations;
4611         } else {
4612             debugging('Bad lang path provided');
4613         }
4614     }
4615
4616     if (isset($CFG->running_installer)) {
4617         $module = 'installer';
4618         $filetocheck = 'installer.php';
4619         $locations[] = $CFG->dirroot.'/install/lang/';
4620         $locations[] = $CFG->dataroot.'/lang/';
4621         $locations[] = $CFG->dirroot.'/lang/';
4622         $defaultlang = 'en_utf8';
4623     } else {
4624         $locations[] = $CFG->dataroot.'/lang/';
4625         $locations[] = $CFG->dirroot.'/lang/';
4626     }
4627
4628 /// Add extra places to look for strings for particular plugin types.
4629     $rules = places_to_search_for_lang_strings();
4630     $exceptions = $rules['__exceptions'];
4631     unset($rules['__exceptions']);
4632
4633     if (!in_array($module, $exceptions)) {
4634         $dividerpos = strpos($module, '_');
4635         if ($dividerpos === false) {
4636             $type = '';
4637             $plugin = $module;
4638         } else {
4639             $type = substr($module, 0, $dividerpos + 1);
4640             $plugin = substr($module, $dividerpos + 1);
4641         }
4642         if (!empty($rules[$type])) {
4643             foreach ($rules[$type] as $location) {
4644                 $locations[] = $CFG->dirroot . "/$location/$plugin/lang/";
4645             }
4646         }
4647     }
4648
4649 /// First check all the normal locations for the string in the current language
4650     $resultstring = '';
4651     foreach ($locations as $location) {
4652         $locallangfile = $location.$lang.'_local'.'/'.$module.'.php';    //first, see if there's a local file
4653         if (file_exists($locallangfile)) {
4654             if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4655                 eval($result);
4656                 return $resultstring;
4657             }
4658         }
4659         //if local directory not found, or particular string does not exist in local direcotry
4660         $langfile = $location.$lang.'/'.$module.'.php';
4661         if (file_exists($langfile)) {
4662             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4663                 eval($result);
4664                 return $resultstring;
4665             }
4666        }
4667     }
4668
4669 /// If the preferred language was English (utf8) we can abort now
4670 /// saving some checks beacuse it's the only "root" lang
4671     if ($lang == 'en_utf8') {
4672         return '[['. $identifier .']]';
4673     }
4674
4675 /// Is a parent language defined?  If so, try to find this string in a parent language file
4676
4677     foreach ($locations as $location) {
4678         $langfile = $location.$lang.'/'.$filetocheck;
4679         if (file_exists($langfile)) {
4680             if ($result = get_string_from_file('parentlanguage', $langfile, "\$parentlang")) {
4681                 eval($result);
4682                 if (!empty($parentlang)) {   // found it!
4683
4684                     //first, see if there's a local file for parent
4685                     $locallangfile = $location.$parentlang.'_local'.'/'.$module.'.php';
4686                     if (file_exists($locallangfile)) {
4687                         if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4688                             eval($result);
4689                             return $resultstring;
4690                         }
4691                     }
4692
4693                     //if local directory not found, or particular string does not exist in local direcotry
4694                     $langfile = $location.$parentlang.'/'.$module.'.php';
4695                     if (file_exists($langfile)) {
4696                         if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4697                             eval($result);
4698                             return $resultstring;
4699                         }
4700                     }
4701                 }
4702             }
4703         }
4704     }
4705
4706 /// Our only remaining option is to try English
4707
4708     foreach ($locations as $location) {
4709         $locallangfile = $location.$defaultlang.'_local/'.$module.'.php';    //first, see if there's a local file
4710         if (file_exists($locallangfile)) {
4711             if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4712                 eval($result);
4713                 return $resultstring;
4714             }
4715         }
4716
4717         //if local_en not found, or string not found in local_en
4718         $langfile = $location.$defaultlang.'/'.$module.'.php';
4719
4720         if (file_exists($langfile)) {
4721             if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4722                 eval($result);
4723                 return $resultstring;
4724             }
4725         }
4726     }
4727
4728 /// And, because under 1.6 en is defined as en_utf8 child, me must try
4729 /// if it hasn't been queried before.
4730     if ($defaultlang  == 'en') {
4731         $defaultlang = 'en_utf8';
4732         foreach ($locations as $location) {
4733             $locallangfile = $location.$defaultlang.'_local/'.$module.'.php';    //first, see if there's a local file
4734             if (file_exists($locallangfile)) {
4735                 if ($result = get_string_from_file($identifier, $locallangfile, "\$resultstring")) {
4736                     eval($result);
4737                     return $resultstring;
4738                 }
4739             }
4740
4741             //if local_en not found, or string not found in local_en
4742             $langfile = $location.$defaultlang.'/'.$module.'.php';
4743
4744             if (file_exists($langfile)) {
4745                 if ($result = get_string_from_file($identifier, $langfile, "\$resultstring")) {
4746                     eval($result);
4747                     return $resultstring;
4748                 }
4749             }
4750         }
4751     }
4752
4753     return '[['.$identifier.']]';  // Last resort
4754 }
4755
4756 /**
4757  * This function is only used from {@link get_string()}.
4758  *
4759  * @internal Only used from get_string, not meant to be public API
4760  * @param string $identifier ?
4761  * @param string $langfile ?
4762  * @param string $destination ?
4763  * @return string|false ?
4764  * @staticvar array $strings Localized strings
4765  * @access private
4766  * @todo Finish documenting this function.
4767  */
4768 function get_string_from_file($identifier, $langfile, $destination) {
4769
4770     static $strings;    // Keep the strings cached in memory.
4771
4772     if (empty($strings[$langfile])) {
4773         $string = array();
4774         include ($langfile);
4775         $strings[$langfile] = $string;
4776     } else {
4777         $string = &$strings[$langfile];
4778     }
4779
4780     if (!isset ($string[$identifier])) {
4781         return false;
4782     }
4783
4784     return $destination .'= sprintf("'. $string[$identifier] .'");';
4785 }
4786
4787 /**
4788  * Converts an array of strings to their localized value.
4789  *
4790  * @param array $array An array of strings
4791  * @param string $module The language module that these strings can be found in.
4792  * @return string
4793  */
4794 function get_strings($array, $module='') {
4795
4796    $string = NULL;
4797    foreach ($array as $item) {
4798        $string->$item = get_string($item, $module);
4799    }
4800    return $string;
4801 }
4802
4803 /**
4804  * Returns a list of language codes and their full names
4805  * hides the _local files from everyone.
4806  * @param bool refreshcache force refreshing of lang cache
4807  * @param bool returnall ignore langlist, return all languages available
4808  * @return array An associative array with contents in the form of LanguageCode => LanguageName
4809  */
4810 function get_list_of_languages($refreshcache=false, $returnall=false) {
4811
4812     global $CFG;
4813
4814     $languages = array();
4815
4816     $filetocheck = 'langconfig.php';
4817
4818     if (!$refreshcache && !$returnall && !empty($CFG->langcache) && file_exists($CFG->dataroot .'/cache/languages')) {
4819 /// read available langs from cache
4820
4821         $lines = file($CFG->dataroot .'/cache/languages');
4822         foreach ($lines as $line) {
4823             $line = trim($line);
4824             if (preg_match('/^(\w+)\s+(.+)/', $line, $matches)) {
4825                 $languages[$matches[1]] = $matches[2];
4826             }
4827         }
4828         unset($lines); unset($line); unset($matches);
4829         return $languages;
4830     }
4831
4832     if (!$returnall && !empty($CFG->langlist)) {
4833 /// return only languages allowed in langlist admin setting
4834
4835         $langlist = explode(',', $CFG->langlist);
4836         // fix short lang names first - non existing langs are skipped anyway...
4837         foreach ($langlist as $lang) {
4838             if (strpos($lang, '_utf8') === false) {
4839                 $langlist[] = $lang.'_utf8';
4840             }
4841         }
4842         // find existing langs from langlist
4843         foreach ($langlist as $lang) {
4844             $lang = trim($lang);   //Just trim spaces to be a bit more permissive
4845             if (strstr($lang, '_local')!==false) {
4846                 continue;
4847             }
4848             if (substr($lang, -5) == '_utf8') {   //Remove the _utf8 suffix from the lang to show
4849                 $shortlang = substr($lang, 0, -5);
4850             } else {
4851                 $shortlang = $lang;
4852             }
4853         /// Search under dirroot/lang
4854             if (file_exists($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck)) {
4855                 include($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck);
4856                 if (!empty($string['thislanguage'])) {
4857                     $languages[$lang] = $string['thislanguage'].' ('. $shortlang .')';
4858                 }
4859                 unset($string);
4860             }
4861         /// And moodledata/lang
4862             if (file_exists($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck)) {
4863                 include($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck);
4864                 if (!empty($string['thislanguage'])) {
4865                     $languages[$lang] = $string['thislanguage'].' ('. $shortlang .')';
4866                 }
4867                 unset($string);
4868             }
4869         }
4870
4871     } else {
4872 /// return all languages available in system
4873     /// Fetch langs from moodle/lang directory
4874         $langdirs = get_list_of_plugins('lang');
4875     /// Fetch langs from moodledata/lang directory
4876         $langdirs2 = get_list_of_plugins('lang', '', $CFG->dataroot);
4877     /// Merge both lists of langs
4878         $langdirs = array_merge($langdirs, $langdirs2);
4879     /// Sort all
4880         asort($langdirs);
4881     /// Get some info from each lang (first from moodledata, then from moodle)
4882         foreach ($langdirs as $lang) {
4883             if (strstr($lang, '_local')!==false) {
4884                 continue;
4885             }
4886             if (substr($lang, -5) == '_utf8') {   //Remove the _utf8 suffix from the lang to show
4887                 $shortlang = substr($lang, 0, -5);
4888             } else {
4889                 $shortlang = $lang;
4890             }
4891         /// Search under moodledata/lang
4892             if (file_exists($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck)) {
4893                 include($CFG->dataroot .'/lang/'. $lang .'/'. $filetocheck);
4894                 if (!empty($string['thislanguage'])) {
4895                     $languages[$lang] = $string['thislanguage'] .' ('. $shortlang .')';
4896                 }
4897                 unset($string);
4898             }
4899         /// And dirroot/lang
4900             if (file_exists($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck)) {
4901                 include($CFG->dirroot .'/lang/'. $lang .'/'. $filetocheck);
4902                 if (!empty($string['thislanguage'])) {
4903                     $languages[$lang] = $string['thislanguage'] .' ('. $shortlang .')';
4904                 }
4905                 unset($string);
4906             }
4907         }
4908     }
4909
4910     if ($refreshcache && !empty($CFG->langcache)) {
4911         if ($returnall) {
4912             // we have a list of all langs only, just delete old cache
4913             @unlink($CFG->dataroot.'/cache/languages');
4914
4915         } else {
4916             // store the list of allowed languages
4917             if ($file = fopen($CFG->dataroot .'/cache/languages', 'w')) {
4918                 foreach ($languages as $key => $value) {
4919                     fwrite($file, "$key $value\n");
4920                 }
4921                 fclose($file);
4922             }
4923         }
4924     }
4925
4926     return $languages;
4927 }
4928
4929 /**
4930  * Returns a list of charset codes. It's hardcoded, so they should be added manually
4931  * (cheking that such charset is supported by the texlib library!)
4932  *
4933  * @return array And associative array with contents in the form of charset => charset
4934  */
4935 function get_list_of_charsets() {
4936
4937     $charsets = array(
4938         'EUC-JP'     => 'EUC-JP',
4939         'ISO-2022-JP'=> 'ISO-2022-JP',
4940         'ISO-8859-1' => 'ISO-8859-1',
4941         'SHIFT-JIS'  => 'SHIFT-JIS',
4942         'GB2312'     => 'GB2312',
4943         'GB18030'    => 'GB18030', // gb18030 not supported by typo and mbstring
4944         'UTF-8'      => 'UTF-8');
4945
4946     asort($charsets);
4947
4948     return $charsets;
4949 }
4950
4951 /**
4952  * Returns a list of country names in the current language
4953  *
4954  * @uses $CFG
4955  * @uses $USER
4956  * @return array
4957  */
4958 function get_list_of_countries() {
4959     global $CFG, $USER;
4960
4961     $lang = current_language();
4962
4963     if (!file_exists($CFG->dirroot .'/lang/'. $lang .'/countries.php') &&
4964         !file_exists($CFG->dataroot.'/lang/'. $lang .'/countries.php')) {
4965         if ($parentlang = get_string('parentlanguage')) {
4966             if (file_exists($CFG->dirroot .'/lang/'. $parentlang .'/countries.php') ||
4967                 file_exists($CFG->dataroot.'/lang/'. $parentlang .'/countries.php')) {
4968                 $lang = $parentlang;
4969             } else {
4970                 $lang = 'en_utf8';  // countries.php must exist in this pack
4971             }
4972         } else {
4973             $lang = 'en_utf8';  // countries.php must exist in this pack
4974         }
4975     }
4976
4977     if (file_exists($CFG->dataroot .'/lang/'. $lang .'/countries.php')) {
4978         include($CFG->dataroot .'/lang/'. $lang .'/countries.php');
4979     } else if (file_exists($CFG->dirroot .'/lang/'. $lang .'/countries.php')) {
4980         include($CFG->dirroot .'/lang/'. $lang .'/countries.php');
4981     }
4982
4983     if (!empty($string)) {
4984         asort($string);
4985     }
4986
4987     return $string;
4988 }
4989
4990 /**
4991  * Returns a list of valid and compatible themes
4992  *
4993  * @uses $CFG
4994  * @return array
4995  */
4996 function get_list_of_themes() {
4997
4998     global $CFG;
4999
5000     $themes = array();
5001
5002     if (!empty($CFG->themelist)) {       // use admin's list of themes
5003         $themelist = explode(',', $CFG->themelist);
5004     } else {
5005         $themelist = get_list_of_plugins("theme");
5006     }
5007
5008     foreach ($themelist as $key => $theme) {
5009         if (!file_exists("$CFG->themedir/$theme/config.php")) {   // bad folder
5010             continue;
5011         }
5012         $THEME = new object();    // Note this is not the global one!!  :-)
5013         include("$CFG->themedir/$theme/config.php");
5014         if (!isset($THEME->sheets)) {   // Not a valid 1.5 theme
5015             continue;
5016         }
5017         $themes[$theme] = $theme;
5018     }
5019     asort($themes);
5020
5021     return $themes;
5022 }
5023
5024
5025 /**
5026  * Returns a list of picture names in the current or specified language
5027  *
5028  * @uses $CFG
5029  * @return array
5030  */
5031 function get_list_of_pixnames($lang = '') {
5032     global $CFG;
5033
5034     if (empty($lang)) {
5035         $lang = current_language();
5036     }
5037
5038     $string = array();
5039
5040     $path = $CFG->dirroot .'/lang/en_utf8/pix.php'; // always exists
5041
5042     if (file_exists($CFG->dataroot .'/lang/'. $lang .'_local/pix.php')) {
5043         $path = $CFG->dataroot .'/lang/'. $lang .'_local/pix.php';
5044
5045     } else if (file_exists($CFG->dirroot .'/lang/'. $lang .'/pix.php')) {
5046         $path = $CFG->dirroot .'/lang/'. $lang .'/pix.php';
5047
5048     } else if (file_exists($CFG->dataroot .'/lang/'. $lang .'/pix.php')) {
5049         $path = $CFG->dataroot .'/lang/'. $lang .'/pix.php';
5050
5051     } else if ($parentlang = get_string('parentlanguage') and $parentlang != '[[parentlanguage]]') {
5052         return get_list_of_pixnames($parentlang); //return pixnames from parent language instead
5053     }
5054
5055     include($path);
5056
5057     return $string;
5058 }
5059
5060 /**
5061  * Returns a list of timezones in the current language
5062  *
5063  * @uses $CFG
5064  * @return array
5065  */
5066 function get_list_of_timezones() {
5067     global $CFG;
5068
5069     static $timezones;
5070
5071     if (!empty($timezones)) {    // This function has been called recently
5072         return $timezones;
5073     }
5074
5075     $timezones = array();
5076
5077     if ($rawtimezones = get_records_sql('SELECT MAX(id), name FROM '.$CFG->prefix.'timezone GROUP BY name')) {
5078         foreach($rawtimezones as $timezone) {
5079             if (!empty($timezone->name)) {
5080                 $timezones[$timezone->name] = get_string(strtolower($timezone->name), 'timezones');
5081                 if (substr($timezones[$timezone->name], 0, 1) == '[') {  // No translation found
5082                     $timezones[$timezone->name] = $timezone->name;
5083                 }
5084             }
5085         }
5086     }
5087
5088     asort($timezones);
5089
5090     for ($i = -13; $i <= 13; $i += .5) {
5091         $tzstring = 'GMT';
5092         if ($i < 0) {
5093             $timezones[sprintf("%.1f", $i)] = $tzstring . $i;
5094         } else if ($i > 0) {
5095             $timezones[sprintf("%.1f", $i)] = $tzstring . '+' . $i;
5096         } else {
5097             $timezones[sprintf("%.1f", $i)] = $tzstring;
5098         }
5099     }
5100
5101     return $timezones;
5102 }
5103
5104 /**
5105  * Returns a list of currencies in the current language
5106  *
5107  * @uses $CFG
5108  * @uses $USER
5109  * @return array
5110  */
5111 function get_list_of_currencies() {
5112     global $CFG, $USER;
5113
5114     $lang = current_language();
5115
5116     if (!file_exists($CFG->dataroot .'/lang/'. $lang .'/currencies.php')) {
5117         if ($parentlang = get_string('parentlanguage')) {
5118             if (file_exists($CFG->dataroot .'/lang/'. $parentlang .'/currencies.php')) {
5119                 $lang = $parentlang;
5120             } else {
5121                 $lang = 'en_utf8';  // currencies.php must exist in this pack
5122             }
5123         } else {
5124             $lang = 'en_utf8';  // currencies.php must exist in this pack
5125         }
5126     }
5127
5128     if (file_exists($CFG->dataroot .'/lang/'. $lang .'/currencies.php')) {
5129         include_once($CFG->dataroot .'/lang/'. $lang .'/currencies.php');
5130     } else {    //if en_utf8 is not installed in dataroot
5131         include_once($CFG->dirroot .'/lang/'. $lang .'/currencies.php');
5132     }
5133
5134     if (!empty($string)) {
5135         asort($string);
5136     }
5137
5138     return $string;
5139 }
5140
5141
5142
5143 /**
5144  * Can include a given document file (depends on second
5145  * parameter) or just return info about it.
5146  *
5147  * @uses $CFG
5148  * @param string $file ?
5149  * @param bool $include ?
5150  * @return ?
5151  * @todo Finish documenting this function
5152  */
5153 function document_file($file, $include=true) {
5154     global $CFG;
5155
5156     $file = clean_filename($file);
5157
5158     if (empty($file)) {
5159         return false;
5160     }
5161
5162     $langs = array(current_language(), get_string('parentlanguage'), 'en');
5163
5164     foreach ($langs as $lang) {
5165         $info = new object();
5166         $info->filepath = $CFG->dirroot .'/lang/'. $lang .'/docs/'. $file;
5167         $info->urlpath  = $CFG->wwwroot .'/lang/'. $lang .'/docs/'. $file;
5168
5169         if (file_exists($info->filepath)) {
5170             if ($include) {
5171                 include($info->filepath);
5172             }
5173             return $info;
5174         }
5175     }
5176
5177     return false;
5178 }
5179
5180 /// ENCRYPTION  ////////////////////////////////////////////////
5181
5182 /**
5183  * rc4encrypt
5184  *
5185  * @param string $data ?
5186  * @return string
5187  * @todo Finish documenting this function
5188  */
5189 function rc4encrypt($data) {
5190     $password = 'nfgjeingjk';
5191     return endecrypt($password, $data, '');
5192 }
5193
5194 /**
5195  * rc4decrypt
5196  *
5197  * @param string $data ?
5198  * @return string
5199  * @todo Finish documenting this function
5200  */
5201 function rc4decrypt($data) {
5202     $password = 'nfgjeingjk';
5203     return endecrypt($password, $data, 'de');
5204 }
5205
5206 /**
5207  * Based on a class by Mukul Sabharwal [mukulsabharwal @ yahoo.com]
5208  *
5209  * @param string $pwd ?
5210  * @param string $data ?
5211  * @param string $case ?
5212  * @return string
5213  * @todo Finish documenting this function
5214  */
5215 function endecrypt ($pwd, $data, $case) {
5216
5217     if ($case == 'de') {
5218         $data = urldecode($data);
5219     }
5220
5221     $key[] = '';
5222     $box[] = '';
5223     $temp_swap = '';
5224     $pwd_length = 0;
5225
5226     $pwd_length = strlen($pwd);
5227
5228     for ($i = 0; $i <= 255; $i++) {
5229         $key[$i] = ord(substr($pwd, ($i % $pwd_length), 1));
5230         $box[$i] = $i;
5231     }
5232
5233     $x = 0;
5234
5235     for ($i = 0; $i <= 255; $i++) {
5236         $x = ($x + $box[$i] + $key[$i]) % 256;
5237         $temp_swap = $box[$i];
5238         $box[$i] = $box[$x];
5239         $box[$x] = $temp_swap;
5240     }
5241
5242     $temp = '';
5243     $k = '';
5244
5245     $cipherby = '';
5246     $cipher = '';
5247
5248     $a = 0;
5249     $j = 0;
5250
5251     for ($i = 0; $i < strlen($data); $i++) {
5252         $a = ($a + 1) % 256;
5253         $j = ($j + $box[$a]) % 256;
5254         $temp = $box[$a];
5255         $box[$a] = $box[$j];
5256         $box[$j] = $temp;
5257         $k = $box[(($box[$a] + $box[$j]) % 256)];
5258         $cipherby = ord(substr($data, $i, 1)) ^ $k;
5259         $cipher .= chr($cipherby);
5260     }
5261
5262     if ($case == 'de') {
5263         $cipher = urldecode(urlencode($cipher));
5264     } else {
5265         $cipher = urlencode($cipher);
5266     }
5267
5268     return $cipher;
5269 }
5270
5271
5272 /// CALENDAR MANAGEMENT  ////////////////////////////////////////////////////////////////
5273
5274
5275 /**
5276  * Call this function to add an event to the calendar table
5277  *  and to call any calendar plugins
5278  *
5279  * @uses $CFG
5280  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field. The object event should include the following:
5281  *  <ul>
5282  *    <li><b>$event->name</b> - Name for the event
5283  *    <li><b>$event->description</b> - Description of the event (defaults to '')
5284  *    <li><b>$event->format</b> - Format for the description (using formatting types defined at the top of weblib.php)
5285  *    <li><b>$event->courseid</b> - The id of the course this event belongs to (0 = all courses)
5286  *    <li><b>$event->groupid</b> - The id of the group this event belongs to (0 = no group)
5287  *    <li><b>$event->userid</b> - The id of the user this event belongs to (0 = no user)
5288  *    <li><b>$event->modulename</b> - Name of the module that creates this event
5289  *    <li><b>$event->instance</b> - Instance of the module that owns this event
5290  *    <li><b>$event->eventtype</b> - The type info together with the module info could
5291  *             be used by calendar plugins to decide how to display event
5292  *    <li><b>$event->timestart</b>- Timestamp for start of event
5293  *    <li><b>$event->timeduration</b> - Duration (defaults to zero)
5294  *    <li><b>$event->visible</b> - 0 if the event should be hidden (e.g. because the activity that created it is hidden)
5295  *  </ul>
5296  * @return int The id number of the resulting record
5297  */
5298  function add_event($event) {
5299
5300     global $CFG;
5301
5302     $event->timemodified = time();
5303
5304     if (!$event->id = insert_record('event', $event)) {
5305         return false;
5306     }
5307
5308     if (!empty($CFG->calendar)) { // call the add_event function of the selected calendar
5309         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5310             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5311             $calendar_add_event = $CFG->calendar.'_add_event';
5312             if (function_exists($calendar_add_event)) {
5313                 $calendar_add_event($event);
5314             }
5315         }
5316     }
5317
5318     return $event->id;
5319 }
5320
5321 /**
5322  * Call this function to update an event in the calendar table
5323  * the event will be identified by the id field of the $event object.
5324  *
5325  * @uses $CFG
5326  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5327  * @return bool
5328  */
5329 function update_event($event) {
5330
5331     global $CFG;
5332
5333     $event->timemodified = time();
5334
5335     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5336         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5337             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5338             $calendar_update_event = $CFG->calendar.'_update_event';
5339             if (function_exists($calendar_update_event)) {
5340                 $calendar_update_event($event);
5341             }
5342         }
5343     }
5344     return update_record('event', $event);
5345 }
5346
5347 /**
5348  * Call this function to delete the event with id $id from calendar table.
5349  *
5350  * @uses $CFG
5351  * @param int $id The id of an event from the 'calendar' table.
5352  * @return array An associative array with the results from the SQL call.
5353  * @todo Verify return type
5354  */
5355 function delete_event($id) {
5356
5357     global $CFG;
5358
5359     if (!empty($CFG->calendar)) { // call the delete_event function of the selected calendar
5360         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5361             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5362             $calendar_delete_event = $CFG->calendar.'_delete_event';
5363             if (function_exists($calendar_delete_event)) {
5364                 $calendar_delete_event($id);
5365             }
5366         }
5367     }
5368     return delete_records('event', 'id', $id);
5369 }
5370
5371 /**
5372  * Call this function to hide an event in the calendar table
5373  * the event will be identified by the id field of the $event object.
5374  *
5375  * @uses $CFG
5376  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5377  * @return array An associative array with the results from the SQL call.
5378  * @todo Verify return type
5379  */
5380 function hide_event($event) {
5381     global $CFG;
5382
5383     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5384         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5385             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5386             $calendar_hide_event = $CFG->calendar.'_hide_event';
5387             if (function_exists($calendar_hide_event)) {
5388                 $calendar_hide_event($event);
5389             }
5390         }
5391     }
5392     return set_field('event', 'visible', 0, 'id', $event->id);
5393 }
5394
5395 /**
5396  * Call this function to unhide an event in the calendar table
5397  * the event will be identified by the id field of the $event object.
5398  *
5399  * @uses $CFG
5400  * @param array $event An associative array representing an event from the calendar table. The event will be identified by the id field.
5401  * @return array An associative array with the results from the SQL call.
5402  * @todo Verify return type
5403  */
5404 function show_event($event) {
5405     global $CFG;
5406
5407     if (!empty($CFG->calendar)) { // call the update_event function of the selected calendar
5408         if (file_exists($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
5409             include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
5410             $calendar_show_event = $CFG->calendar.'_show_event';
5411             if (function_exists($calendar_show_event)) {
5412                 $calendar_show_event($event);
5413             }
5414         }
5415     }
5416     return set_field('event', 'visible', 1, 'id', $event->id);
5417 }
5418
5419
5420 /// ENVIRONMENT CHECKING  ////////////////////////////////////////////////////////////
5421
5422 /**
5423  * Lists plugin directories within some directory
5424  *
5425  * @uses $CFG
5426  * @param string $plugin dir under we'll look for plugins (defaults to 'mod')
5427  * @param string $exclude dir name to exclude from the list (defaults to none)
5428  * @param string $basedir full path to the base dir where $plugin resides (defaults to $CFG->dirroot)
5429  * @return array of plugins found under the requested parameters
5430  */
5431 function get_list_of_plugins($plugin='mod', $exclude='', $basedir='') {
5432
5433     global $CFG;
5434
5435     $plugins = array();
5436
5437     if (empty($basedir)) {
5438
5439         # This switch allows us to use the appropiate theme directory - and potentialy alternatives for other plugins
5440         switch ($plugin) {
5441         case "theme":
5442             $basedir = $CFG->themedir;
5443             break;
5444
5445         default:
5446             $basedir = $CFG->dirroot .'/'. $plugin;
5447         }
5448
5449     } else {
5450         $basedir = $basedir .'/'. $plugin;
5451     }
5452
5453     if (file_exists($basedir) && filetype($basedir) == 'dir') {
5454         $dirhandle = opendir($basedir);
5455         while (false !== ($dir = readdir($dirhandle))) {
5456             $firstchar = substr($dir, 0, 1);
5457             if ($firstchar == '.' or $dir == 'CVS' or $dir == '_vti_cnf' or $dir == $exclude) {
5458                 continue;
5459             }
5460             if (filetype($basedir .'/'. $dir) != 'dir') {
5461                 continue;
5462             }
5463             $plugins[] = $dir;
5464         }
5465         closedir($dirhandle);
5466     }
5467     if ($plugins) {
5468         asort($plugins);
5469     }
5470     return $plugins;
5471 }
5472
5473 /**
5474  * Returns true if the current version of PHP is greater that the specified one.
5475  *
5476  * @param string $version The version of php being tested.
5477  * @return bool
5478  */
5479 function check_php_version($version='4.1.0') {
5480     return (version_compare(phpversion(), $version) >= 0);
5481 }
5482
5483
5484 /**
5485  * Checks to see if is a browser matches the specified
5486  * brand and is equal or better version.
5487  *
5488  * @uses $_SERVER
5489  * @param string $brand The browser identifier being tested
5490  * @param int $version The version of the browser
5491  * @return bool true if the given version is below that of the detected browser
5492  */
5493  function check_browser_version($brand='MSIE', $version=5.5) {
5494     if (empty($_SERVER['HTTP_USER_AGENT'])) {
5495         return false;
5496     }
5497
5498     $agent = $_SERVER['HTTP_USER_AGENT'];
5499
5500     switch ($brand) {
5501
5502       case 'Camino':   /// Mozilla Firefox browsers
5503
5504               if (preg_match("/Camino\/([0-9\.]+)/i", $agent, $match)) {
5505                   if (version_compare($match[1], $version) >= 0) {
5506                       return true;
5507                   }
5508               }
5509               break;
5510
5511
5512       case 'Firefox':   /// Mozilla Firefox browsers
5513
5514           if (preg_match("/Firefox\/([0-9\.]+)/i", $agent, $match)) {
5515               if (version_compare($match[1], $version) >= 0) {
5516                   return true;
5517               }
5518           }
5519           break;
5520
5521
5522       case 'Gecko':   /// Gecko based browsers
5523
5524           if (substr_count($agent, 'Camino')) {
5525               // MacOS X Camino support
5526               $version = 20041110;
5527           }
5528
5529           // the proper string - Gecko/CCYYMMDD Vendor/Version
5530           // Faster version and work-a-round No IDN problem.
5531           if (preg_match("/Gecko\/([0-9]+)/i", $agent, $match)) {
5532               if ($match[1] > $version) {
5533                       return true;
5534                   }
5535               }
5536           break;
5537
5538
5539       case 'MSIE':   /// Internet Explorer
5540
5541           if (strpos($agent, 'Opera')) {     // Reject Opera
5542               return false;
5543           }
5544           $string = explode(';', $agent);
5545           if (!isset($string[1])) {
5546               return false;
5547           }
5548           $string = explode(' ', trim($string[1]));
5549           if (!isset($string[0]) and !isset($string[1])) {
5550               return false;
5551           }
5552           if ($string[0] == $brand and (float)$string[1] >= $version ) {
5553               return true;
5554           }
5555           break;
5556
5557       case 'Opera':  /// Opera
5558
5559           if (preg_match("/Opera\/([0-9\.]+)/i", $agent, $match)) {
5560               if (version_compare($match[1], $version) >= 0) {
5561                   return true;
5562               }
5563           }
5564           break;
5565
5566       case 'Safari':  /// Safari
5567           // Look for AppleWebKit, excluding strings with OmniWeb, Shiira and SimbianOS
5568           if (strpos($agent, 'OmniWeb')) { // Reject OmniWeb
5569               return false;
5570           } elseif (strpos($agent, 'Shiira')) { // Reject Shiira
5571               return false;
5572           } elseif (strpos($agent, 'SimbianOS')) { // Reject SimbianOS
5573               return false;
5574           }
5575
5576           if (preg_match("/AppleWebKit\/([0-9]+)/i", $agent, $match)) {
5577               if (version_compare($match[1], $version) >= 0) {
5578                   return true;
5579               }
5580           }
5581
5582           break;
5583
5584     }
5585
5586     return false;
5587 }
5588
5589 /**
5590  * This function makes the return value of ini_get consistent if you are
5591  * setting server directives through the .htaccess file in apache.
5592  * Current behavior for value set from php.ini On = 1, Off = [blank]
5593  * Current behavior for value set from .htaccess On = On, Off = Off
5594  * Contributed by jdell @ unr.edu
5595  *
5596  * @param string $ini_get_arg ?
5597  * @return bool
5598  * @todo Finish documenting this function
5599  */
5600 function ini_get_bool($ini_get_arg) {
5601     $temp = ini_get($ini_get_arg);
5602
5603     if ($temp == '1' or strtolower($temp) == 'on') {
5604         return true;
5605     }
5606     return false;
5607 }
5608
5609 /**
5610  * Compatibility stub to provide backward compatibility
5611  *
5612  * Determines if the HTML editor is enabled.
5613  * @deprecated Use {@link can_use_html_editor()} instead.
5614  */
5615  function can_use_richtext_editor() {
5616     return can_use_html_editor();
5617 }
5618
5619 /**
5620  * Determines if the HTML editor is enabled.
5621  *
5622  * This depends on site and user
5623  * settings, as well as the current browser being used.
5624  *
5625  * @return string|false Returns false if editor is not being used, otherwise
5626  * returns 'MSIE' or 'Gecko'.
5627  */
5628  function can_use_html_editor() {
5629     global $USER, $CFG;
5630
5631     if (!empty($USER->htmleditor) and !empty($CFG->htmleditor)) {
5632         if (check_browser_version('MSIE', 5.5)) {
5633             return 'MSIE';
5634         } else if (check_browser_version('Gecko', 20030516)) {
5635             return 'Gecko';
5636         }
5637     }
5638     return false;
5639 }
5640
5641 /**
5642  * Hack to find out the GD version by parsing phpinfo output
5643  *
5644  * @return int GD version (1, 2, or 0)
5645  */
5646 function check_gd_version() {
5647     $gdversion = 0;
5648
5649     if (function_exists('gd_info')){
5650         $gd_info = gd_info();
5651         if (substr_count($gd_info['GD Version'], '2.')) {
5652             $gdversion = 2;
5653         } else if (substr_count($gd_info['GD Version'], '1.')) {
5654             $gdversion = 1;
5655         }
5656
5657     } else {
5658         ob_start();
5659         phpinfo(8);
5660         $phpinfo = ob_get_contents();
5661         ob_end_clean();
5662
5663         $phpinfo = explode("\n", $phpinfo);
5664
5665
5666         foreach ($phpinfo as $text) {
5667             $parts = explode('</td>', $text);
5668             foreach ($parts as $key => $val) {
5669                 $parts[$key] = trim(strip_tags($val));
5670             }
5671             if ($parts[0] == 'GD Version') {
5672                 if (substr_count($parts[1], '2.0')) {
5673                     $parts[1] = '2.0';
5674                 }
5675                 $gdversion = intval($parts[1]);
5676             }
5677         }
5678     }
5679
5680     return $gdversion;   // 1, 2 or 0
5681 }
5682
5683 /**
5684  * Determine if moodle installation requires update
5685  *
5686  * Checks version numbers of main code and all modules to see
5687  * if there are any mismatches
5688  *
5689  * @uses $CFG
5690  * @return bool
5691  */
5692 function moodle_needs_upgrading() {
5693     global $CFG;
5694
5695     $version = null;
5696     include_once($CFG->dirroot .'/version.php');  # defines $version and upgrades
5697     if ($CFG->version) {
5698         if ($version > $CFG->version) {
5699             return true;
5700         }
5701         if ($mods = get_list_of_plugins('mod')) {
5702             foreach ($mods as $mod) {
5703                 $fullmod = $CFG->dirroot .'/mod/'. $mod;
5704                 $module = new object();
5705                 if (!is_readable($fullmod .'/version.php')) {
5706                     notify('Module "'. $mod .'" is not readable - check permissions');
5707                     continue;
5708                 }
5709                 include_once($fullmod .'/version.php');  # defines $module with version etc
5710                 if ($currmodule = get_record('modules', 'name', $mod)) {
5711                     if ($module->version > $currmodule->version) {
5712                         return true;
5713                     }
5714                 }
5715             }
5716         }
5717     } else {
5718         return true;
5719     }
5720     return false;
5721 }
5722
5723
5724 /// MISCELLANEOUS ////////////////////////////////////////////////////////////////////
5725
5726 /**
5727  * Notify admin users or admin user of any failed logins (since last notification).
5728  *
5729  * @uses $CFG
5730  * @uses $db
5731  * @uses HOURSECS
5732  */
5733 function notify_login_failures() {
5734     global $CFG, $db;
5735
5736     switch ($CFG->notifyloginfailures) {
5737         case 'mainadmin' :
5738             $recip = array(get_admin());
5739             break;
5740         case 'alladmins':
5741             $recip = get_admins();
5742             break;
5743     }
5744
5745     if (empty($CFG->lastnotifyfailure)) {
5746         $CFG->lastnotifyfailure=0;
5747     }
5748
5749     // we need to deal with the threshold stuff first.
5750     if (empty($CFG->notifyloginthreshold)) {
5751         $CFG->notifyloginthreshold = 10; // default to something sensible.
5752     }
5753
5754     $notifyipsrs = $db->Execute('SELECT ip FROM '. $CFG->prefix .'log WHERE time > '. $CFG->lastnotifyfailure .'
5755                           AND module=\'login\' AND action=\'error\' GROUP BY ip HAVING count(*) > '. $CFG->notifyloginthreshold);
5756
5757     $notifyusersrs = $db->Execute('SELECT info FROM '. $CFG->prefix .'log WHERE time > '. $CFG->lastnotifyfailure .'
5758                           AND module=\'login\' AND action=\'error\' GROUP BY info HAVING count(*) > '. $CFG->notifyloginthreshold);
5759
5760     if ($notifyipsrs) {
5761         $ipstr = '';
5762         while ($row = rs_fetch_next_record($notifyipsrs)) {
5763             $ipstr .= "'". $row->ip ."',";
5764         }
5765         rs_close($notifyipsrs);
5766         $ipstr = substr($ipstr,0,strlen($ipstr)-1);
5767     }
5768     if ($notifyusersrs) {
5769         $userstr = '';
5770         while ($row = rs_fetch_next_record($notifyusersrs)) {
5771             $userstr .= "'". $row->info ."',";
5772         }
5773         rs_close($notifyusersrs);
5774         $userstr = substr($userstr,0,strlen($userstr)-1);
5775     }
5776
5777     if (strlen($userstr) > 0 || strlen($ipstr) > 0) {
5778         $count = 0;
5779         $logs = get_logs('time > '. $CFG->lastnotifyfailure .' AND module=\'login\' AND action=\'error\' '
5780                  .((strlen($ipstr) > 0 && strlen($userstr) > 0) ? ' AND ( ip IN ('. $ipstr .') OR info IN ('. $userstr .') ) '
5781                  : ((strlen($ipstr) != 0) ? ' AND ip IN ('. $ipstr .') ' : ' AND info IN ('. $userstr .') ')), 'l.time DESC', '', '', $count);
5782
5783         // if we haven't run in the last hour and we have something useful to report and we are actually supposed to be reporting to somebody
5784         if (is_array($recip) and count($recip) > 0 and ((time() - HOURSECS) > $CFG->lastnotifyfailure)
5785             and is_array($logs) and count($logs) > 0) {
5786
5787             $message = '';
5788             $site = get_site();
5789             $subject = get_string('notifyloginfailuressubject', '', format_string($site->fullname));
5790             $message .= get_string('notifyloginfailuresmessagestart', '', $CFG->wwwroot)
5791                  .(($CFG->lastnotifyfailure != 0) ? '('.userdate($CFG->lastnotifyfailure).')' : '')."\n\n";
5792             foreach ($logs as $log) {
5793                 $log->time = userdate($log->time);
5794                 $message .= get_string('notifyloginfailuresmessage','',$log)."\n";
5795             }
5796             $message .= "\n\n".get_string('notifyloginfailuresmessageend','',$CFG->wwwroot)."\n\n";
5797             foreach ($recip as $admin) {
5798                 mtrace('Emailing '. $admin->username .' about '. count($logs) .' failed login attempts');
5799                 email_to_user($admin,get_admin(),$subject,$message);
5800             }
5801             $conf = new object();
5802             $conf->name = 'lastnotifyfailure';
5803             $conf->value = time();
5804             if ($current = get_record('config', 'name', 'lastnotifyfailure')) {
5805                 $conf->id = $current->id;
5806                 if (! update_record('config', $conf)) {
5807                     mtrace('Could not update last notify time');
5808                 }
5809
5810             } else if (! insert_record('config', $conf)) {
5811                 mtrace('Could not set last notify time');
5812             }
5813         }
5814     }
5815 }
5816
5817 /**
5818  * moodle_setlocale
5819  *
5820  * @uses $CFG
5821  * @param string $locale ?
5822  * @todo Finish documenting this function
5823  */
5824 function moodle_setlocale($locale='') {
5825
5826     global $CFG;
5827
5828     static $currentlocale = ''; // last locale caching
5829
5830     $oldlocale = $currentlocale;
5831
5832 /// Fetch the correct locale based on ostype
5833     if($CFG->ostype == 'WINDOWS') {
5834         $stringtofetch = 'localewin';
5835     } else {
5836         $stringtofetch = 'locale';
5837     }
5838
5839 /// the priority is the same as in get_string() - parameter, config, course, session, user, global language
5840     if (!empty($locale)) {
5841         $currentlocale = $locale;
5842     } else if (!empty($CFG->locale)) { // override locale for all language packs
5843         $currentlocale = $CFG->locale;
5844     } else {
5845         $currentlocale = get_string($stringtofetch);
5846     }
5847
5848 /// do nothing if locale already set up
5849     if ($oldlocale == $currentlocale) {
5850         return;
5851     }
5852
5853 /// Due to some strange BUG we cannot set the LC_TIME directly, so we fetch current values,
5854 /// set LC_ALL and then set values again. Just wondering why we cannot set LC_ALL only??? - stronk7
5855 /// Some day, numeric, monetary and other categories should be set too, I think. :-/
5856
5857 /// Get current values
5858     $monetary= setlocale (LC_MONETARY, 0);
5859     $numeric = setlocale (LC_NUMERIC, 0);
5860     $ctype   = setlocale (LC_CTYPE, 0);
5861     if ($CFG->ostype != 'WINDOWS') {
5862         $messages= setlocale (LC_MESSAGES, 0);
5863     }
5864 /// Set locale to all
5865     setlocale (LC_ALL, $currentlocale);
5866 /// Set old values
5867     setlocale (LC_MONETARY, $monetary);
5868     setlocale (LC_NUMERIC, $numeric);
5869     if ($CFG->ostype != 'WINDOWS') {
5870         setlocale (LC_MESSAGES, $messages);
5871     }
5872     if ($currentlocale == 'tr_TR' or $currentlocale == 'tr_TR.UTF-8') { // To workaround a well-known PHP problem with Turkish letter Ii
5873         setlocale (LC_CTYPE, $ctype);
5874     }
5875 }
5876
5877 /**
5878  * Converts string to lowercase using most compatible function available.
5879  *
5880  * @param string $string The string to convert to all lowercase characters.
5881  * @param string $encoding The encoding on the string.
5882  * @return string
5883  * @todo Add examples of calling this function with/without encoding types
5884  * @deprecated Use textlib->strtolower($text) instead.
5885  */
5886 function moodle_strtolower ($string, $encoding='') {
5887
5888     //If not specified use utf8
5889     if (empty($encoding)) {
5890         $encoding = 'UTF-8';
5891     }
5892     //Use text services
5893     $textlib = textlib_get_instance();
5894
5895     return $textlib->strtolower($string, $encoding);
5896 }
5897
5898 /**
5899  * Count words in a string.
5900  *
5901  * Words are defined as things between whitespace.
5902  *
5903  * @param string $string The text to be searched for words.
5904  * @return int The count of words in the specified string
5905  */
5906 function count_words($string) {
5907     $string = strip_tags($string);
5908     return count(preg_split("/\w\b/", $string)) - 1;
5909 }
5910
5911 /** Count letters in a string.
5912  *
5913  * Letters are defined as chars not in tags and different from whitespace.
5914  *
5915  * @param string $string The text to be searched for letters.
5916  * @return int The count of letters in the specified text.
5917  */
5918 function count_letters($string) {
5919 /// Loading the textlib singleton instance. We are going to need it.
5920     $textlib = textlib_get_instance();
5921
5922     $string = strip_tags($string); // Tags are out now
5923     $string = ereg_replace('[[:space:]]*','',$string); //Whitespace are out now
5924
5925     return $textlib->strlen($string);
5926 }
5927
5928 /**
5929  * Generate and return a random string of the specified length.
5930  *
5931  * @param int $length The length of the string to be created.
5932  * @return string
5933  */
5934 function random_string ($length=15) {
5935     $pool  = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
5936     $pool .= 'abcdefghijklmnopqrstuvwxyz';
5937     $pool .= '0123456789';
5938     $poollen = strlen($pool);
5939     mt_srand ((double) microtime() * 1000000);
5940     $string = '';
5941     for ($i = 0; $i < $length; $i++) {
5942         $string .= substr($pool, (mt_rand()%($poollen)), 1);
5943     }
5944     return $string;
5945 }
5946
5947 /*
5948  * Given some text (which may contain HTML) and an ideal length,
5949  * this function truncates the text neatly on a word boundary if possible
5950  */
5951 function shorten_text($text, $ideal=30) {
5952
5953    global $CFG;
5954
5955
5956    $i = 0;
5957    $tag = false;
5958    $length = strlen($text);
5959    $count = 0;
5960    $stopzone = false;
5961    $truncate = 0;
5962
5963    if ($length <= $ideal) {
5964        return $text;
5965    }
5966
5967    for ($i=0; $i<$length; $i++) {
5968        $char = $text[$i];
5969
5970        switch ($char) {
5971            case "<":
5972                $tag = true;
5973                break;
5974            case ">":
5975                $tag = false;
5976                break;
5977            default:
5978                if (!$tag) {
5979                    if ($stopzone) {
5980                        if ($char == '.' or $char == ' ') {
5981                            $truncate = $i+1;
5982                            break 2;
5983                        } else if (ord($char) >= 0xE0) {  // Chinese/Japanese/Korean text
5984                            $truncate = $i;               // can be truncated at any UTF-8
5985                            break 2;                      // character boundary.
5986                        }
5987                    }
5988                    $count++;
5989                }
5990                break;
5991        }
5992        if (!$stopzone) {
5993            if ($count > $ideal) {
5994                $stopzone = true;
5995            }
5996        }
5997    }
5998
5999    if (!$truncate) {
6000        $truncate = $i;
6001    }
6002
6003    $ellipse = ($truncate < $length) ? '...' : '';
6004
6005    return substr($text, 0, $truncate).$ellipse;
6006 }
6007
6008
6009 /**
6010  * Given dates in seconds, how many weeks is the date from startdate
6011  * The first week is 1, the second 2 etc ...
6012  *
6013  * @uses WEEKSECS
6014  * @param ? $startdate ?
6015  * @param ? $thedate ?
6016  * @return string
6017  * @todo Finish documenting this function
6018  */
6019 function getweek ($startdate, $thedate) {
6020     if ($thedate < $startdate) {   // error
6021         return 0;
6022     }
6023
6024     return floor(($thedate - $startdate) / WEEKSECS) + 1;
6025 }
6026
6027 /**
6028  * returns a randomly generated password of length $maxlen.  inspired by
6029  * {@link http://www.phpbuilder.com/columns/jesus19990502.php3}
6030  *
6031  * @param int $maxlength  The maximum size of the password being generated.
6032  * @return string
6033  */
6034 function generate_password($maxlen=10) {
6035     global $CFG;
6036
6037     $fillers = '1234567890!$-+';
6038     $wordlist = file($CFG->wordlist);
6039
6040     srand((double) microtime() * 1000000);
6041     $word1 = trim($wordlist[rand(0, count($wordlist) - 1)]);
6042     $word2 = trim($wordlist[rand(0, count($wordlist) - 1)]);
6043     $filler1 = $fillers[rand(0, strlen($fillers) - 1)];
6044
6045     return substr($word1 . $filler1 . $word2, 0, $maxlen);
6046 }
6047
6048 /**
6049  * Given a float, prints it nicely.
6050  * Localized floats must not be used in calculations!
6051  *
6052  * @param float $flaot The float to print
6053  * @param int $places The number of decimal places to print.
6054  * @param bool $localized use localized decimal separator
6055  * @return string locale float
6056  */
6057 function format_float($float, $decimalpoints=1, $localized=true) {
6058     if (is_null($float)) {
6059         return '';
6060     }
6061     if ($localized) {
6062         return number_format($float, $decimalpoints, get_string('decsep'), '');
6063     } else {
6064         return number_format($float, $decimalpoints, '.', '');
6065     }
6066 }
6067
6068 /**
6069  * Converts locale specific floating point/comma number back to standard PHP float value
6070  * Do NOT try to do any math operations before this conversion on any user submitted floats!
6071  *
6072  * @param  string $locale_float locale aware float representation
6073  */
6074 function unformat_float($locale_float) {
6075     $locale_float = trim($locale_float);
6076
6077     if ($locale_float == '') {
6078         return null;
6079     }
6080
6081     $locale_float = str_replace(' ', '', $locale_float); // no spaces - those might be used as thousand separators
6082
6083     return (float)str_replace(get_string('decsep'), '.', $locale_float);
6084 }
6085
6086 /**
6087  * Given a simple array, this shuffles it up just like shuffle()
6088  * Unlike PHP's shuffle() this function works on any machine.
6089  *
6090  * @param array $array The array to be rearranged
6091  * @return array
6092  */
6093 function swapshuffle($array) {
6094
6095     srand ((double) microtime() * 10000000);
6096     $last = count($array) - 1;
6097     for ($i=0;$i<=$last;$i++) {
6098         $from = rand(0,$last);
6099         $curr = $array[$i];
6100         $array[$i] = $array[$from];
6101         $array[$from] = $curr;
6102     }
6103     return $array;
6104 }
6105
6106 /**
6107  * Like {@link swapshuffle()}, but works on associative arrays
6108  *
6109  * @param array $array The associative array to be rearranged
6110  * @return array
6111  */
6112 function swapshuffle_assoc($array) {
6113 ///
6114
6115     $newkeys = swapshuffle(array_keys($array));
6116     foreach ($newkeys as $newkey) {
6117         $newarray[$newkey] = $array[$newkey];
6118     }
6119     return $newarray;
6120 }
6121
6122 /**
6123  * Given an arbitrary array, and a number of draws,
6124  * this function returns an array with that amount
6125  * of items.  The indexes are retained.
6126  *
6127  * @param array $array ?
6128  * @param ? $draws ?
6129  * @return ?
6130  * @todo Finish documenting this function
6131  */
6132 function draw_rand_array($array, $draws) {
6133     srand ((double) microtime() * 10000000);
6134
6135     $return = array();
6136
6137     $last = count($array);
6138
6139     if ($draws > $last) {
6140         $draws = $last;
6141     }
6142
6143     while ($draws > 0) {
6144         $last--;
6145
6146         $keys = array_keys($array);
6147         $rand = rand(0, $last);
6148
6149         $return[$keys[$rand]] = $array[$keys[$rand]];
6150         unset($array[$keys[$rand]]);
6151
6152         $draws--;
6153     }
6154
6155     return $return;
6156 }
6157
6158 /**
6159  * microtime_diff
6160  *
6161  * @param string $a ?
6162  * @param string $b ?
6163  * @return string
6164  * @todo Finish documenting this function
6165  */
6166 function microtime_diff($a, $b) {
6167     list($a_dec, $a_sec) = explode(' ', $a);
6168     list($b_dec, $b_sec) = explode(' ', $b);
6169     return $b_sec - $a_sec + $b_dec - $a_dec;
6170 }
6171
6172 /**
6173  * Given a list (eg a,b,c,d,e) this function returns
6174  * an array of 1->a, 2->b, 3->c etc
6175  *
6176  * @param array $list ?
6177  * @param string $separator ?
6178  * @todo Finish documenting this function
6179  */
6180 function make_menu_from_list($list, $separator=',') {
6181
6182     $array = array_reverse(explode($separator, $list), true);
6183     foreach ($array as $key => $item) {
6184         $outarray[$key+1] = trim($item);
6185     }
6186     return $outarray;
6187 }
6188
6189 /**
6190  * Creates an array that represents all the current grades that
6191  * can be chosen using the given grading type.  Negative numbers
6192  * are scales, zero is no grade, and positive numbers are maximum
6193  * grades.
6194  *
6195  * @param int $gradingtype ?
6196  * return int
6197  * @todo Finish documenting this function
6198  */
6199 function make_grades_menu($gradingtype) {
6200     $grades = array();
6201     if ($gradingtype < 0) {
6202         if ($scale = get_record('scale', 'id', - $gradingtype)) {
6203             return make_menu_from_list($scale->scale);
6204         }
6205     } else if ($gradingtype > 0) {
6206         for ($i=$gradingtype; $i>=0; $i--) {
6207             $grades[$i] = $i .' / '. $gradingtype;
6208         }
6209         return $grades;
6210     }
6211     return $grades;
6212 }
6213
6214 /**
6215  * This function returns the nummber of activities
6216  * using scaleid in a courseid
6217  *
6218  * @param int $courseid ?
6219  * @param int $scaleid ?
6220  * @return int
6221  * @todo Finish documenting this function
6222  */
6223 function course_scale_used($courseid, $scaleid) {
6224
6225     global $CFG;
6226
6227     $return = 0;
6228
6229     if (!empty($scaleid)) {
6230         if ($cms = get_course_mods($courseid)) {
6231             foreach ($cms as $cm) {
6232                 //Check cm->name/lib.php exists
6233                 if (file_exists($CFG->dirroot.'/mod/'.$cm->modname.'/lib.php')) {
6234                     include_once($CFG->dirroot.'/mod/'.$cm->modname.'/lib.php');
6235                     $function_name = $cm->modname.'_scale_used';
6236                     if (function_exists($function_name)) {
6237                         if ($function_name($cm->instance,$scaleid)) {
6238                             $return++;
6239                         }
6240                     }
6241                 }
6242             }
6243         }
6244
6245         // check if any course grade item makes use of the scale
6246         $return += count_records('grade_items', 'courseid', $courseid, 'scaleid', $scaleid);
6247     }
6248     return $return;
6249 }
6250
6251 /**
6252  * This function returns the nummber of activities
6253  * using scaleid in the entire site
6254  *
6255  * @param int $scaleid ?
6256  * @return int
6257  * @todo Finish documenting this function. Is return type correct?
6258  */
6259 function site_scale_used($scaleid,&$courses) {
6260
6261     global $CFG;
6262
6263     $return = 0;
6264
6265     if (!is_array($courses) || count($courses) == 0) {
6266         $courses = get_courses("all",false,"c.id,c.shortname");
6267     }
6268
6269     if (!empty($scaleid)) {
6270         if (is_array($courses) && count($courses) > 0) {
6271             foreach ($courses as $course) {
6272                 $return += course_scale_used($course->id,$scaleid);
6273             }
6274         }
6275     }
6276     return $return;
6277 }
6278
6279 /**
6280  * make_unique_id_code
6281  *
6282  * @param string $extra ?
6283  * @return string
6284  * @todo Finish documenting this function
6285  */
6286 function make_unique_id_code($extra='') {
6287
6288     $hostname = 'unknownhost';
6289     if (!empty($_SERVER['HTTP_HOST'])) {
6290         $hostname = $_SERVER['HTTP_HOST'];
6291     } else if (!empty($_ENV['HTTP_HOST'])) {
6292         $hostname = $_ENV['HTTP_HOST'];
6293     } else if (!empty($_SERVER['SERVER_NAME'])) {
6294         $hostname = $_SERVER['SERVER_NAME'];
6295     } else if (!empty($_ENV['SERVER_NAME'])) {
6296         $hostname = $_ENV['SERVER_NAME'];
6297     }
6298
6299     $date = gmdate("ymdHis");
6300
6301     $random =  random_string(6);
6302
6303     if ($extra) {
6304         return $hostname .'+'. $date .'+'. $random .'+'. $extra;
6305     } else {
6306         return $hostname .'+'. $date .'+'. $random;
6307     }
6308 }
6309
6310
6311 /**
6312  * Function to check the passed address is within the passed subnet
6313  *
6314  * The parameter is a comma separated string of subnet definitions.
6315  * Subnet strings can be in one of three formats:
6316  *   1: xxx.xxx.xxx.xxx/xx
6317  *   2: xxx.xxx
6318  *   3: xxx.xxx.xxx.xxx-xxx   //a range of IP addresses in the last group.
6319  * Code for type 1 modified from user posted comments by mediator at
6320  * {@link http://au.php.net/manual/en/function.ip2long.php}
6321  *
6322  * @param string $addr    The address you are checking
6323  * @param string $subnetstr    The string of subnet addresses
6324  * @return bool
6325  */
6326 function address_in_subnet($addr, $subnetstr) {
6327
6328     $subnets = explode(',', $subnetstr);
6329     $found = false;
6330     $addr = trim($addr);
6331
6332     foreach ($subnets as $subnet) {
6333         $subnet = trim($subnet);
6334         if (strpos($subnet, '/') !== false) { /// type 1
6335             list($ip, $mask) = explode('/', $subnet);
6336             $mask = 0xffffffff << (32 - $mask);
6337             $found = ((ip2long($addr) & $mask) == (ip2long($ip) & $mask));
6338         } else if (strpos($subnet, '-') !== false)  {/// type 3
6339             $subnetparts = explode('.', $subnet);
6340             $addrparts = explode('.', $addr);
6341             $subnetrange = explode('-', array_pop($subnetparts));
6342             if (count($subnetrange) == 2) {
6343                 $lastaddrpart = array_pop($addrparts);
6344                 $found = ($subnetparts == $addrparts &&
6345                         $subnetrange[0] <= $lastaddrpart && $lastaddrpart <= $subnetrange[1]);
6346             }
6347         } else { /// type 2
6348             $found = (strpos($addr, $subnet) === 0);
6349         }
6350
6351         if ($found) {
6352             break;
6353         }
6354     }
6355     return $found;
6356 }
6357
6358 /**
6359  * This function sets the $HTTPSPAGEREQUIRED global
6360  * (used in some parts of moodle to change some links)
6361  * and calculate the proper wwwroot to be used
6362  *
6363  * By using this function properly, we can ensure 100% https-ized pages
6364  * at our entire discretion (login, forgot_password, change_password)
6365  */
6366 function httpsrequired() {
6367
6368     global $CFG, $HTTPSPAGEREQUIRED;
6369
6370     if (!empty($CFG->loginhttps)) {
6371         $HTTPSPAGEREQUIRED = true;
6372         $CFG->httpswwwroot = str_replace('http:', 'https:', $CFG->wwwroot);
6373         $CFG->httpsthemewww = str_replace('http:', 'https:', $CFG->themewww);
6374
6375         // change theme URLs to https
6376         theme_setup();
6377
6378     } else {
6379         $CFG->httpswwwroot = $CFG->wwwroot;
6380         $CFG->httpsthemewww = $CFG->themewww;
6381     }
6382 }
6383
6384 /**
6385  * For outputting debugging info
6386  *
6387  * @uses STDOUT
6388  * @param string $string ?
6389  * @param string $eol ?
6390  * @todo Finish documenting this function
6391  */
6392 function mtrace($string, $eol="\n", $sleep=0) {
6393
6394     if (defined('STDOUT')) {
6395         fwrite(STDOUT, $string.$eol);
6396     } else {
6397         echo $string . $eol;
6398     }
6399
6400     flush();
6401
6402     //delay to keep message on user's screen in case of subsequent redirect
6403     if ($sleep) {
6404         sleep($sleep);
6405     }
6406 }
6407
6408 //Replace 1 or more slashes or backslashes to 1 slash
6409 function cleardoubleslashes ($path) {
6410     return preg_replace('/(\/|\\\){1,}/','/',$path);
6411 }
6412
6413 function zip_files ($originalfiles, $destination) {
6414 //Zip an array of files/dirs to a destination zip file
6415 //Both parameters must be FULL paths to the files/dirs
6416
6417     global $CFG;
6418
6419     //Extract everything from destination
6420     $path_parts = pathinfo(cleardoubleslashes($destination));
6421     $destpath = $path_parts["dirname"];       //The path of the zip file
6422     $destfilename = $path_parts["basename"];  //The name of the zip file
6423     $extension = $path_parts["extension"];    //The extension of the file
6424
6425     //If no file, error
6426     if (empty($destfilename)) {
6427         return false;
6428     }
6429
6430     //If no extension, add it
6431     if (empty($extension)) {
6432         $extension = 'zip';
6433         $destfilename = $destfilename.'.'.$extension;
6434     }
6435
6436     //Check destination path exists
6437     if (!is_dir($destpath)) {
6438         return false;
6439     }
6440
6441     //Check destination path is writable. TODO!!
6442
6443     //Clean destination filename
6444     $destfilename = clean_filename($destfilename);
6445
6446     //Now check and prepare every file
6447     $files = array();
6448     $origpath = NULL;
6449
6450     foreach ($originalfiles as $file) {  //Iterate over each file
6451         //Check for every file
6452         $tempfile = cleardoubleslashes($file); // no doubleslashes!
6453         //Calculate the base path for all files if it isn't set
6454         if ($origpath === NULL) {
6455             $origpath = rtrim(cleardoubleslashes(dirname($tempfile)), "/");
6456         }
6457         //See if the file is readable
6458         if (!is_readable($tempfile)) {  //Is readable
6459             continue;
6460         }
6461         //See if the file/dir is in the same directory than the rest
6462         if (rtrim(cleardoubleslashes(dirname($tempfile)), "/") != $origpath) {
6463             continue;
6464         }
6465         //Add the file to the array
6466         $files[] = $tempfile;
6467     }
6468
6469     //Everything is ready:
6470     //    -$origpath is the path where ALL the files to be compressed reside (dir).
6471     //    -$destpath is the destination path where the zip file will go (dir).
6472     //    -$files is an array of files/dirs to compress (fullpath)
6473     //    -$destfilename is the name of the zip file (without path)
6474
6475     //print_object($files);                  //Debug
6476
6477     if (empty($CFG->zip)) {    // Use built-in php-based zip function
6478
6479         include_once("$CFG->libdir/pclzip/pclzip.lib.php");
6480         //rewrite filenames because the old method with PCLZIP_OPT_REMOVE_PATH does not work under win32
6481         $zipfiles = array();
6482         $start = strlen($origpath)+1;
6483         foreach($files as $file) {
6484             $tf = array();
6485             $tf[PCLZIP_ATT_FILE_NAME] = $file;
6486             $tf[PCLZIP_ATT_FILE_NEW_FULL_NAME] = substr($file, $start);
6487             $zipfiles[] = $tf;
6488         }
6489         //create the archive
6490         $archive = new PclZip(cleardoubleslashes("$destpath/$destfilename"));
6491         if (($list = $archive->create($zipfiles) == 0)) {
6492             notice($archive->errorInfo(true));
6493             return false;
6494         }
6495
6496     } else {                   // Use external zip program
6497
6498         $filestozip = "";
6499         foreach ($files as $filetozip) {
6500             $filestozip .= escapeshellarg(basename($filetozip));
6501             $filestozip .= " ";
6502         }
6503         //Construct the command
6504         $separator = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? ' &' : ' ;';
6505         $command = 'cd '.escapeshellarg($origpath).$separator.
6506                     escapeshellarg($CFG->zip).' -r '.
6507                     escapeshellarg(cleardoubleslashes("$destpath/$destfilename")).' '.$filestozip;
6508         //All converted to backslashes in WIN
6509         if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6510             $command = str_replace('/','\\',$command);
6511         }
6512         Exec($command);
6513     }
6514     return true;
6515 }
6516
6517 function unzip_file ($zipfile, $destination = '', $showstatus = true) {
6518 //Unzip one zip file to a destination dir
6519 //Both parameters must be FULL paths
6520 //If destination isn't specified, it will be the
6521 //SAME directory where the zip file resides.
6522
6523     global $CFG;
6524
6525     //Extract everything from zipfile
6526     $path_parts = pathinfo(cleardoubleslashes($zipfile));
6527     $zippath = $path_parts["dirname"];       //The path of the zip file
6528     $zipfilename = $path_parts["basename"];  //The name of the zip file
6529     $extension = $path_parts["extension"];    //The extension of the file
6530
6531     //If no file, error
6532     if (empty($zipfilename)) {
6533         return false;
6534     }
6535
6536     //If no extension, error
6537     if (empty($extension)) {
6538         return false;
6539     }
6540
6541     //Clear $zipfile
6542     $zipfile = cleardoubleslashes($zipfile);
6543
6544     //Check zipfile exists
6545     if (!file_exists($zipfile)) {
6546         return false;
6547     }
6548
6549     //If no destination, passed let's go with the same directory
6550     if (empty($destination)) {
6551         $destination = $zippath;
6552     }
6553
6554     //Clear $destination
6555     $destpath = rtrim(cleardoubleslashes($destination), "/");
6556
6557     //Check destination path exists
6558     if (!is_dir($destpath)) {
6559         return false;
6560     }
6561
6562     //Check destination path is writable. TODO!!
6563
6564     //Everything is ready:
6565     //    -$zippath is the path where the zip file resides (dir)
6566     //    -$zipfilename is the name of the zip file (without path)
6567     //    -$destpath is the destination path where the zip file will uncompressed (dir)
6568
6569     $list = null;
6570
6571     if (empty($CFG->unzip)) {    // Use built-in php-based unzip function
6572
6573         include_once("$CFG->libdir/pclzip/pclzip.lib.php");
6574         $archive = new PclZip(cleardoubleslashes("$zippath/$zipfilename"));
6575         if (!$list = $archive->extract(PCLZIP_OPT_PATH, $destpath,
6576                                        PCLZIP_CB_PRE_EXTRACT, 'unzip_cleanfilename',
6577                                        PCLZIP_OPT_EXTRACT_DIR_RESTRICTION, $destpath)) {
6578             notice($archive->errorInfo(true));
6579             return false;
6580         }
6581
6582     } else {                     // Use external unzip program
6583
6584         $separator = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? ' &' : ' ;';
6585         $redirection = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' ? '' : ' 2>&1';
6586
6587         $command = 'cd '.escapeshellarg($zippath).$separator.
6588                     escapeshellarg($CFG->unzip).' -o '.
6589                     escapeshellarg(cleardoubleslashes("$zippath/$zipfilename")).' -d '.
6590                     escapeshellarg($destpath).$redirection;
6591         //All converted to backslashes in WIN
6592         if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6593             $command = str_replace('/','\\',$command);
6594         }
6595         Exec($command,$list);
6596     }
6597
6598     //Display some info about the unzip execution
6599     if ($showstatus) {
6600         unzip_show_status($list,$destpath);
6601     }
6602
6603     return true;
6604 }
6605
6606 function unzip_cleanfilename ($p_event, &$p_header) {
6607 //This function is used as callback in unzip_file() function
6608 //to clean illegal characters for given platform and to prevent directory traversal.
6609 //Produces the same result as info-zip unzip.
6610     $p_header['filename'] = ereg_replace('[[:cntrl:]]', '', $p_header['filename']); //strip control chars first!
6611     $p_header['filename'] = ereg_replace('\.\.+', '', $p_header['filename']); //directory traversal protection
6612     if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
6613         $p_header['filename'] = ereg_replace('[:*"?<>|]', '_', $p_header['filename']); //replace illegal chars
6614         $p_header['filename'] = ereg_replace('^([a-zA-Z])_', '\1:', $p_header['filename']); //repair drive letter
6615     } else {
6616         //Add filtering for other systems here
6617         // BSD: none (tested)
6618         // Linux: ??
6619         // MacosX: ??
6620     }
6621     $p_header['filename'] = cleardoubleslashes($p_header['filename']); //normalize the slashes/backslashes
6622     return 1;
6623 }
6624
6625 function unzip_show_status ($list,$removepath) {
6626 //This function shows the results of the unzip execution
6627 //depending of the value of the $CFG->zip, results will be
6628 //text or an array of files.
6629
6630     global $CFG;
6631
6632     if (empty($CFG->unzip)) {    // Use built-in php-based zip function
6633         $strname = get_string("name");
6634         $strsize = get_string("size");
6635         $strmodified = get_string("modified");
6636         $strstatus = get_string("status");
6637         echo "<table width=\"640\">";
6638         echo "<tr><th class=\"header\" scope=\"col\">$strname</th>";
6639         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strsize</th>";
6640         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strmodified</th>";
6641         echo "<th class=\"header\" align=\"right\" scope=\"col\">$strstatus</th></tr>";
6642         foreach ($list as $item) {
6643             echo "<tr>";
6644             $item['filename'] = str_replace(cleardoubleslashes($removepath).'/', "", $item['filename']);
6645             print_cell("left", s($item['filename']));
6646             if (! $item['folder']) {
6647                 print_cell("right", display_size($item['size']));
6648             } else {
6649                 echo "<td>&nbsp;</td>";
6650             }
6651             $filedate  = userdate($item['mtime'], get_string("strftimedatetime"));
6652             print_cell("right", $filedate);
6653             print_cell("right", $item['status']);
6654             echo "</tr>";
6655         }
6656         echo "</table>";
6657
6658     } else {                   // Use external zip program
6659         print_simple_box_start("center");
6660         echo "<pre>";
6661         foreach ($list as $item) {
6662             echo s(str_replace(cleardoubleslashes($removepath.'/'), '', $item)).'<br />';
6663         }
6664         echo "</pre>";
6665         print_simple_box_end();
6666     }
6667 }
6668
6669 /**
6670  * Returns most reliable client address
6671  *
6672  * @return string The remote IP address
6673  */
6674  function getremoteaddr() {
6675     if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
6676         return cleanremoteaddr($_SERVER['HTTP_CLIENT_IP']);
6677     }
6678     if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
6679         return cleanremoteaddr($_SERVER['HTTP_X_FORWARDED_FOR']);
6680     }
6681     if (!empty($_SERVER['REMOTE_ADDR'])) {
6682         return cleanremoteaddr($_SERVER['REMOTE_ADDR']);
6683     }
6684     return '';
6685 }
6686
6687 /**
6688  * Cleans a remote address ready to put into the log table
6689  */
6690 function cleanremoteaddr($addr) {
6691     $originaladdr = $addr;
6692     $matches = array();
6693     // first get all things that look like IP addresses.
6694     if (!preg_match_all('/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/',$addr,$matches,PREG_SET_ORDER)) {
6695         return '';
6696     }
6697     $goodmatches = array();
6698     $lanmatches = array();
6699     foreach ($matches as $match) {
6700         //        print_r($match);
6701         // check to make sure it's not an internal address.
6702         // the following are reserved for private lans...
6703         // 10.0.0.0 - 10.255.255.255
6704         // 172.16.0.0 - 172.31.255.255
6705         // 192.168.0.0 - 192.168.255.255
6706         // 169.254.0.0 -169.254.255.255
6707         $bits = explode('.',$match[0]);
6708         if (count($bits) != 4) {
6709             // weird, preg match shouldn't give us it.
6710             continue;
6711         }
6712         if (($bits[0] == 10)
6713             || ($bits[0] == 172 && $bits[1] >= 16 && $bits[1] <= 31)
6714             || ($bits[0] == 192 && $bits[1] == 168)
6715             || ($bits[0] == 169 && $bits[1] == 254)) {
6716             $lanmatches[] = $match[0];
6717             continue;
6718         }
6719         // finally, it's ok
6720         $goodmatches[] = $match[0];
6721     }
6722     if (!count($goodmatches)) {
6723         // perhaps we have a lan match, it's probably better to return that.
6724         if (!count($lanmatches)) {
6725             return '';
6726         } else {
6727             return array_pop($lanmatches);
6728         }
6729     }
6730     if (count($goodmatches) == 1) {
6731         return $goodmatches[0];
6732     }
6733     error_log("NOTICE: cleanremoteaddr gives us something funny: $originaladdr had ".count($goodmatches)." matches");
6734     // we need to return something, so
6735     return array_pop($goodmatches);
6736 }
6737
6738 /**
6739  * file_put_contents is only supported by php 5.0 and higher
6740  * so if it is not predefined, define it here
6741  *
6742  * @param $file full path of the file to write
6743  * @param $contents contents to be sent
6744  * @return number of bytes written (false on error)
6745  */
6746 if(!function_exists('file_put_contents')) {
6747     function file_put_contents($file, $contents) {
6748         $result = false;
6749         if ($f = fopen($file, 'w')) {
6750             $result = fwrite($f, $contents);
6751             fclose($f);
6752         }
6753         return $result;
6754     }
6755 }
6756
6757 /**
6758  * The clone keyword is only supported from PHP 5 onwards.
6759  * The behaviour of $obj2 = $obj1 differs fundamentally
6760  * between PHP 4 and PHP 5. In PHP 4 a copy of $obj1 was
6761  * created, in PHP 5 $obj1 is referenced. To create a copy
6762  * in PHP 5 the clone keyword was introduced. This function
6763  * simulates this behaviour for PHP < 5.0.0.
6764  * See also: http://mjtsai.com/blog/2004/07/15/php-5-object-references/
6765  *
6766  * Modified 2005-09-29 by Eloy (from Julian Sedding proposal)
6767  * Found a better implementation (more checks and possibilities) from PEAR:
6768  * http://cvs.php.net/co.php/pear/PHP_Compat/Compat/Function/clone.php
6769  *
6770  * @param object $obj
6771  * @return object
6772  */
6773 if(!check_php_version('5.0.0')) {
6774 // the eval is needed to prevent PHP 5 from getting a parse error!
6775 eval('
6776     function clone($obj) {
6777     /// Sanity check
6778         if (!is_object($obj)) {
6779             user_error(\'clone() __clone method called on non-object\', E_USER_WARNING);
6780             return;
6781         }
6782
6783     /// Use serialize/unserialize trick to deep copy the object
6784         $obj = unserialize(serialize($obj));
6785
6786     /// If there is a __clone method call it on the "new" class
6787         if (method_exists($obj, \'__clone\')) {
6788             $obj->__clone();
6789         }
6790
6791         return $obj;
6792     }
6793
6794     // Supply the PHP5 function scandir() to older versions.
6795     function scandir($directory) {
6796         $files = array();
6797         if ($dh = opendir($directory)) {
6798             while (($file = readdir($dh)) !== false) {
6799                $files[] = $file;
6800             }
6801             closedir($dh);
6802         }
6803         return $files;
6804     }
6805
6806     // Supply the PHP5 function array_combine() to older versions.
6807     function array_combine($keys, $values) {
6808         if (!is_array($keys) || !is_array($values) || count($keys) != count($values)) {
6809             return false;
6810         }
6811         reset($values);
6812         $result = array();
6813         foreach ($keys as $key) {
6814             $result[$key] = current($values);
6815             next($values);
6816         }
6817         return $result;
6818     }
6819 ');
6820 }
6821
6822 /**
6823  * This function will make a complete copy of anything it's given,
6824  * regardless of whether it's an object or not.
6825  * @param mixed $thing
6826  * @return mixed
6827  */
6828 function fullclone($thing) {
6829     return unserialize(serialize($thing));
6830 }
6831
6832
6833 /*
6834  * This function expects to called during shutdown
6835  * should be set via register_shutdown_function()
6836  * in lib/setup.php .
6837  *
6838  * Right now we do it only if we are under apache, to
6839  * make sure apache children that hog too much mem are
6840  * killed.
6841  *
6842  */
6843 function moodle_request_shutdown() {
6844
6845     global $CFG;
6846
6847     // initially, we are only ever called under apache
6848     // but check just in case
6849     if (function_exists('apache_child_terminate')
6850         && function_exists('memory_get_usage')
6851         && ini_get_bool('child_terminate')) {
6852         if (empty($CFG->apachemaxmem)) {
6853             $CFG->apachemaxmem = 25000000; // default 25MiB
6854         }
6855         if (memory_get_usage() > (int)$CFG->apachemaxmem) {
6856             trigger_error('Mem usage over $CFG->apachemaxmem: marking child for reaping.');
6857             @apache_child_terminate();
6858         }
6859     }
6860     if (defined('MDL_PERF') || (!empty($CFG->perfdebug) and $CFG->perfdebug > 7)) {
6861         if (defined('MDL_PERFTOLOG')) {
6862             $perf = get_performance_info();
6863             error_log("PERF: " . $perf['txt']);
6864         }
6865         if (defined('MDL_PERFINC')) {
6866             $inc = get_included_files();
6867             $ts  = 0;
6868             foreach($inc as $f) {
6869                 if (preg_match(':^/:', $f)) {
6870                     $fs  =  filesize($f);
6871                     $ts  += $fs;
6872                     $hfs =  display_size($fs);
6873                     error_log(substr($f,strlen($CFG->dirroot)) . " size: $fs ($hfs)"
6874                               , NULL, NULL, 0);
6875                 } else {
6876                     error_log($f , NULL, NULL, 0);
6877                 }
6878             }
6879             if ($ts > 0 ) {
6880                 $hts = display_size($ts);
6881                 error_log("Total size of files included: $ts ($hts)");
6882             }
6883         }
6884     }
6885 }
6886
6887 /**
6888  * If new messages are waiting for the current user, then return
6889  * Javascript code to create a popup window
6890  *
6891  * @return string Javascript code
6892  */
6893 function message_popup_window() {
6894     global $USER;
6895
6896     $popuplimit = 30;     // Minimum seconds between popups
6897
6898     if (!defined('MESSAGE_WINDOW')) {
6899         if (isset($USER->id) and !isguestuser()) {
6900             if (!isset($USER->message_lastpopup)) {
6901                 $USER->message_lastpopup = 0;
6902             }
6903             if ((time() - $USER->message_lastpopup) > $popuplimit) {  /// It's been long enough
6904                 if (get_user_preferences('message_showmessagewindow', 1) == 1) {
6905                     if (count_records_select('message', 'useridto = \''.$USER->id.'\' AND timecreated > \''.$USER->message_lastpopup.'\'')) {
6906                         $USER->message_lastpopup = time();
6907                         return '<script type="text/javascript">'."\n//<![CDATA[\n openpopup('/message/index.php', 'message',
6908                         'menubar=0,location=0,scrollbars,status,resizable,width=400,height=500', 0);\n//]]>\n</script>";
6909                     }
6910                 }
6911             }
6912         }
6913     }
6914
6915     return '';
6916 }
6917
6918 // Used to make sure that $min <= $value <= $max
6919 function bounded_number($min, $value, $max) {
6920     if($value < $min) {
6921         return $min;
6922     }
6923     if($value > $max) {
6924         return $max;
6925     }
6926     return $value;
6927 }
6928
6929 function array_is_nested($array) {
6930     foreach ($array as $value) {
6931         if (is_array($value)) {
6932             return true;
6933         }
6934     }
6935     return false;
6936 }
6937
6938 /**
6939  *** get_performance_info() pairs up with init_performance_info()
6940  *** loaded in setup.php. Returns an array with 'html' and 'txt'
6941  *** values ready for use, and each of the individual stats provided
6942  *** separately as well.
6943  ***
6944  **/
6945 function get_performance_info() {
6946     global $CFG, $PERF, $rcache;
6947
6948     $info = array();
6949     $info['html'] = '';         // holds userfriendly HTML representation
6950     $info['txt']  = me() . ' '; // holds log-friendly representation
6951
6952     $info['realtime'] = microtime_diff($PERF->starttime, microtime());
6953
6954     $info['html'] .= '<span class="timeused">'.$info['realtime'].' secs</span> ';
6955     $info['txt'] .= 'time: '.$info['realtime'].'s ';
6956
6957     if (function_exists('memory_get_usage')) {
6958         $info['memory_total'] = memory_get_usage();
6959         $info['memory_growth'] = memory_get_usage() - $PERF->startmemory;
6960         $info['html'] .= '<span class="memoryused">RAM: '.display_size($info['memory_total']).'</span> ';
6961         $info['txt']  .= 'memory_total: '.$info['memory_total'].'B (' . display_size($info['memory_total']).') memory_growth: '.$info['memory_growth'].'B ('.display_size($info['memory_growth']).') ';
6962     }
6963
6964     $inc = get_included_files();
6965     //error_log(print_r($inc,1));
6966     $info['includecount'] = count($inc);
6967     $info['html'] .= '<span class="included">Included '.$info['includecount'].' files</span> ';
6968     $info['txt']  .= 'includecount: '.$info['includecount'].' ';
6969
6970     if (!empty($PERF->dbqueries)) {
6971         $info['dbqueries'] = $PERF->dbqueries;
6972         $info['html'] .= '<span class="dbqueries">DB queries '.$info['dbqueries'].'</span> ';
6973         $info['txt'] .= 'dbqueries: '.$info['dbqueries'].' ';
6974     }
6975
6976     if (!empty($PERF->logwrites)) {
6977         $info['logwrites'] = $PERF->logwrites;
6978         $info['html'] .= '<span class="logwrites">Log writes '.$info['logwrites'].'</span> ';
6979         $info['txt'] .= 'logwrites: '.$info['logwrites'].' ';
6980     }
6981
6982     if (!empty($PERF->profiling) && $PERF->profiling) {
6983         require_once($CFG->dirroot .'/lib/profilerlib.php');
6984         $info['html'] .= '<span class="profilinginfo">'.Profiler::get_profiling(array('-R')).'</span>';
6985     }
6986
6987     if (function_exists('posix_times')) {
6988         $ptimes = posix_times();
6989         if (is_array($ptimes)) {
6990             foreach ($ptimes as $key => $val) {
6991                 $info[$key] = $ptimes[$key] -  $PERF->startposixtimes[$key];
6992             }
6993             $info['html'] .= "<span class=\"posixtimes\">ticks: $info[ticks] user: $info[utime] sys: $info[stime] cuser: $info[cutime] csys: $info[cstime]</span> ";
6994             $info['txt'] .= "ticks: $info[ticks] user: $info[utime] sys: $info[stime] cuser: $info[cutime] csys: $info[cstime] ";
6995         }
6996     }
6997
6998     // Grab the load average for the last minute
6999     // /proc will only work under some linux configurations
7000     // while uptime is there under MacOSX/Darwin and other unices
7001     if (is_readable('/proc/loadavg') && $loadavg = @file('/proc/loadavg')) {
7002         list($server_load) = explode(' ', $loadavg[0]);
7003         unset($loadavg);
7004     } else if ( function_exists('is_executable') && is_executable('/usr/bin/uptime') && $loadavg = `/usr/bin/uptime` ) {
7005         if (preg_match('/load averages?: (\d+[\.,:]\d+)/', $loadavg, $matches)) {
7006             $server_load = $matches[1];
7007         } else {
7008             trigger_error('Could not parse uptime output!');
7009         }
7010     }
7011     if (!empty($server_load)) {
7012         $info['serverload'] = $server_load;
7013         $info['html'] .= '<span class="serverload">Load average: '.$info['serverload'].'</span> ';
7014         $info['txt'] .= "serverload: {$info['serverload']} ";
7015     }
7016
7017     if (isset($rcache->hits) && isset($rcache->misses)) {
7018         $info['rcachehits'] = $rcache->hits;
7019         $info['rcachemisses'] = $rcache->misses;
7020         $info['html'] .= '<span class="rcache">Record cache hit/miss ratio : '.
7021             "{$rcache->hits}/{$rcache->misses}</span> ";
7022         $info['txt'] .= 'rcache: '.
7023             "{$rcache->hits}/{$rcache->misses} ";
7024     }
7025     $info['html'] = '<div class="performanceinfo">'.$info['html'].'</div>';
7026     return $info;
7027 }
7028
7029 function apd_get_profiling() {
7030     return shell_exec('pprofp -u ' . ini_get('apd.dumpdir') . '/pprof.' . getmypid() . '.*');
7031 }
7032
7033 function remove_dir($dir, $content_only=false) {
7034     // if content_only=true then delete all but
7035     // the directory itself
7036
7037     $handle = opendir($dir);
7038     while (false!==($item = readdir($handle))) {
7039         if($item != '.' && $item != '..') {
7040             if(is_dir($dir.'/'.$item)) {
7041                 remove_dir($dir.'/'.$item);
7042             }else{
7043                 unlink($dir.'/'.$item);
7044             }
7045         }
7046     }
7047     closedir($handle);
7048     if ($content_only) {
7049         return true;
7050     }
7051     return rmdir($dir);
7052 }
7053
7054 /**
7055  * Function to check if a directory exists and optionally create it.
7056  *
7057  * @param string absolute directory path
7058  * @param boolean create directory if does not exist
7059  * @param boolean create directory recursively
7060  *
7061  * @return boolean true if directory exists or created
7062  */
7063 function check_dir_exists($dir, $create=false, $recursive=false) {
7064
7065     global $CFG;
7066
7067     $status = true;
7068
7069     if(!is_dir($dir)) {
7070         if (!$create) {
7071             $status = false;
7072         } else {
7073             umask(0000);
7074             if ($recursive) {
7075                 // PHP 5.0 has recursive mkdir parameter, but 4.x does not :-(
7076                 $dir = str_replace('\\', '/', $dir); //windows compatibility
7077                 $dirs = explode('/', $dir);
7078                 $dir = array_shift($dirs).'/'; //skip root or drive letter
7079                 foreach ($dirs as $part) {
7080                     if ($part == '') {
7081                         continue;
7082                     }
7083                     $dir .= $part.'/';
7084                     if (!is_dir($dir)) {
7085                         if (!mkdir($dir, $CFG->directorypermissions)) {
7086                             $status = false;
7087                             break;
7088                         }
7089                     }
7090                 }
7091             } else {
7092                 $status = mkdir($dir, $CFG->directorypermissions);
7093             }
7094         }
7095     }
7096     return $status;
7097 }
7098
7099 function report_session_error() {
7100     global $CFG, $FULLME;
7101
7102     if (empty($CFG->lang)) {
7103         $CFG->lang = "en";
7104     }
7105     // Set up default theme and locale
7106     theme_setup();
7107     moodle_setlocale();
7108
7109     //clear session cookies
7110     setcookie('MoodleSession'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
7111     setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath);
7112     //increment database error counters
7113     if (isset($CFG->session_error_counter)) {
7114         set_config('session_error_counter', 1 + $CFG->session_error_counter);
7115     } else {
7116         set_config('session_error_counter', 1);
7117     }
7118     redirect($FULLME, get_string('sessionerroruser2', 'error'), 5);
7119 }
7120
7121
7122 /**
7123  * Detect if an object or a class contains a given property
7124  * will take an actual object or the name of a class
7125  * @param mix $obj Name of class or real object to test
7126  * @param string $property name of property to find
7127  * @return bool true if property exists
7128  */
7129 function object_property_exists( $obj, $property ) {
7130     if (is_string( $obj )) {
7131         $properties = get_class_vars( $obj );
7132     }
7133     else {
7134         $properties = get_object_vars( $obj );
7135     }
7136     return array_key_exists( $property, $properties );
7137 }
7138
7139
7140 /**
7141  * Detect a custom script replacement in the data directory that will
7142  * replace an existing moodle script
7143  * @param string $urlpath path to the original script
7144  * @return string full path name if a custom script exists
7145  * @return bool false if no custom script exists
7146  */
7147 function custom_script_path($urlpath='') {
7148     global $CFG;
7149
7150     // set default $urlpath, if necessary
7151     if (empty($urlpath)) {
7152         $urlpath = qualified_me(); // e.g. http://www.this-server.com/moodle/this-script.php
7153     }
7154
7155     // $urlpath is invalid if it is empty or does not start with the Moodle wwwroot
7156     if (empty($urlpath) or (strpos($urlpath, $CFG->wwwroot) === false )) {
7157         return false;
7158     }
7159
7160     // replace wwwroot with the path to the customscripts folder and clean path
7161     $scriptpath = $CFG->customscripts . clean_param(substr($urlpath, strlen($CFG->wwwroot)), PARAM_PATH);
7162
7163     // remove the query string, if any
7164     if (($strpos = strpos($scriptpath, '?')) !== false) {
7165         $scriptpath = substr($scriptpath, 0, $strpos);
7166     }
7167
7168     // remove trailing slashes, if any
7169     $scriptpath = rtrim($scriptpath, '/\\');
7170
7171     // append index.php, if necessary
7172     if (is_dir($scriptpath)) {
7173         $scriptpath .= '/index.php';
7174     }
7175
7176     // check the custom script exists
7177     if (file_exists($scriptpath)) {
7178         return $scriptpath;
7179     } else {
7180         return false;
7181     }
7182 }
7183
7184 /**
7185  * Wrapper function to load necessary editor scripts
7186  * to $CFG->editorsrc array. Params can be coursei id
7187  * or associative array('courseid' => value, 'name' => 'editorname').
7188  * @uses $CFG
7189  * @param mixed $args Courseid or associative array.
7190  */
7191 function loadeditor($args) {
7192     global $CFG;
7193     include($CFG->libdir .'/editorlib.php');
7194     return editorObject::loadeditor($args);
7195 }
7196
7197 /**
7198  * Returns whether or not the user object is a remote MNET user. This function
7199  * is in moodlelib because it does not rely on loading any of the MNET code.
7200  *
7201  * @param object $user A valid user object
7202  * @return bool        True if the user is from a remote Moodle.
7203  */
7204 function is_mnet_remote_user($user) {
7205     global $CFG;
7206
7207     if (!isset($CFG->mnet_localhost_id)) {
7208         include_once $CFG->dirroot . '/mnet/lib.php';
7209         $env = new mnet_environment();
7210         $env->init();
7211         unset($env);
7212     }
7213
7214     return (!empty($user->mnethostid) && $user->mnethostid != $CFG->mnet_localhost_id);
7215 }
7216
7217 /**
7218  * Checks if a given plugin is in the list of enabled enrolment plugins.
7219  *
7220  * @param string $auth Enrolment plugin.
7221  * @return boolean Whether the plugin is enabled.
7222  */
7223 function is_enabled_enrol($enrol='') {
7224     global $CFG;
7225
7226     // use the global default if not specified
7227     if ($enrol == '') {
7228         $enrol = $CFG->enrol;
7229     }
7230     return in_array($enrol, explode(',', $CFG->enrol_plugins_enabled));
7231 }
7232
7233 /**
7234  * This function will search for browser prefereed languages, setting Moodle
7235  * to use the best one available if $SESSION->lang is undefined
7236  */
7237 function setup_lang_from_browser() {
7238
7239     global $CFG, $SESSION, $USER;
7240
7241     if (!empty($SESSION->lang) or !empty($USER->lang)) {
7242         // Lang is defined in session or user profile, nothing to do
7243         return;
7244     }
7245
7246     if (!isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) { // There isn't list of browser langs, nothing to do
7247         return;
7248     }
7249
7250 /// Extract and clean langs from headers
7251     $rawlangs = $_SERVER['HTTP_ACCEPT_LANGUAGE'];
7252     $rawlangs = str_replace('-', '_', $rawlangs);         // we are using underscores
7253     $rawlangs = explode(',', $rawlangs);                  // Convert to array
7254     $langs = array();
7255
7256     $order = 1.0;
7257     foreach ($rawlangs as $lang) {
7258         if (strpos($lang, ';') === false) {
7259             $langs[(string)$order] = $lang;
7260             $order = $order-0.01;
7261         } else {
7262             $parts = explode(';', $lang);
7263             $pos = strpos($parts[1], '=');
7264             $langs[substr($parts[1], $pos+1)] = $parts[0];
7265         }
7266     }
7267     krsort($langs, SORT_NUMERIC);
7268
7269     $langlist = get_list_of_languages();
7270
7271 /// Look for such langs under standard locations
7272     foreach ($langs as $lang) {
7273         $lang = strtolower(clean_param($lang.'_utf8', PARAM_SAFEDIR)); // clean it properly for include
7274         if (!array_key_exists($lang, $langlist)) {
7275             continue; // language not allowed, try next one
7276         }
7277         if (file_exists($CFG->dataroot .'/lang/'. $lang) or file_exists($CFG->dirroot .'/lang/'. $lang)) {
7278             $SESSION->lang = $lang; /// Lang exists, set it in session
7279             break; /// We have finished. Go out
7280         }
7281     }
7282     return;
7283 }
7284
7285
7286 ////////////////////////////////////////////////////////////////////////////////
7287
7288 function is_newnav($navigation) {
7289     if (is_array($navigation) && !empty($navigation['newnav'])) {
7290         return true;
7291     } else {
7292         return false;
7293     }
7294 }
7295
7296 /**
7297  * Checks whether the given variable name is defined as a variable within the given object.
7298  * @note This will NOT work with stdClass objects, which have no class variables.
7299  * @param string $var The variable name
7300  * @param object $object The object to check
7301  * @return boolean
7302  */
7303 function in_object_vars($var, $object) {
7304     $class_vars = get_class_vars(get_class($object));
7305     $class_vars = array_keys($class_vars);
7306     return in_array($var, $class_vars);
7307 }
7308
7309 /**
7310  * Returns an array without repeated objects.
7311  * This function is similar to array_unique, but for arrays that have objects as values
7312  *
7313  * @param unknown_type $array
7314  * @param unknown_type $keep_key_assoc
7315  * @return unknown
7316  */
7317 function object_array_unique($array, $keep_key_assoc = true) {
7318     $duplicate_keys = array();
7319     $tmp         = array();
7320
7321     foreach ($array as $key=>$val) {
7322         // convert objects to arrays, in_array() does not support objects
7323         if (is_object($val)) {
7324             $val = (array)$val;
7325         }
7326
7327         if (!in_array($val, $tmp)) {
7328             $tmp[] = $val;
7329         } else {
7330             $duplicate_keys[] = $key;
7331         }
7332     }
7333
7334     foreach ($duplicate_keys as $key) {
7335         unset($array[$key]);
7336     }
7337
7338     return $keep_key_assoc ? $array : array_values($array);
7339 }
7340
7341 // vim:autoindent:expandtab:shiftwidth=4:tabstop=4:tw=140:
7342 ?>